Poll regarding rounding of Bitcoin amounts in clients

[Andreas Schildbach]

The purpose of my post is getting opinions about rounding of Bitcoin amounts.

Most clients already cut of insignificant zeros at the end. So for example, 1.22000000 gets 1.22. Still, especially if you use currency conversion frequently, you'll have a lot of crude amounts (like 0.31745883 for a burger) in your wallet. In my opinion, this makes it hard to read, especially for non-technical people.

Bitcoin Wallet currently implements a labs feature that allows you to round to either 4, 6 or 8 digits after the comma (see Preferences -> Labs -> Precision of Bitcoin values). Note that when entering amounts yourself (such as when sending a payment) you still can use any precision you like. Also, the setting of course doesn't affect any internal calculations, so there is no "adding up of rounding errors" and stuff like that.

My questions go to all of you, not only Bitcoin Wallet users:

Would you use such a feature in your client?
Do you think it makes sense, also for non-technical people?
Do you find 0.1255 easier to read than 0.125501?
Should we kind of standardize the options (4, 6 and 8 digits) for all clients?
I deliberately left the option of 2 digits out, because we're way past the "0.01 is equivalent to a penny/cent" era. Do you miss it still?
Which option should be default?

[1715645550]

1715645550

[Sukrim]

I'd recommend displaying mBTC or even µBTC by default. Additionally group thousands/millions like this: 1.00000000 BTC = 1 000 000.00 µBTC

[Andreas Schildbach]

I'd recommend displaying mBTC or even µBTC by default. Additionally group thousands/millions like this: 1.00000000 BTC = 1 000 000.00 µBTC

Ah, I forgot to mention. The "moving of the comma" topic is not the main topic of this poll.

Are groups of 1000 (as in 1 000 000) also used after the comma? I thought only before.

[Scrat Acorns]

Maybe it's just me but I don't like rounding. What I also don't like is unformatted floats.

IMHO:
1.00000000 -> 1.00
1.00001000 -> 1.00001

But then again I might be weird.

Edit: If it's an optional feature then I'm all for it.

[Andreas Schildbach]

Maybe it's just me but I don't like rounding. What I also don't like is unformatted floats.

IMHO:
1.00000000 -> 1.00
1.00001000 -> 1.00001

What's an "unformatted float"? So you like the right side and dislike the left side?

And - more to this topic - you dislike 1.00001 -> 1.0000 (because of 4 digits of precision)?

Edit: If it's an optional feature then I'm all for it.

Sure, it will stay optional (8 digits of precision means no rounding at all).

[dserrano5]

Would you use such a feature in your client?
Do you think it makes sense, also for non-technical people?
Do you find 0.1255 easier to read than 0.125501?
Should we kind of standardize the options (4, 6 and 8 digits) for all clients?

No.
E.g. my parents? yeah prolly.
No.
Wait some time, then ask people what do they use most.

[matakaonew]

Would you use such a feature in your client?
 - yeah if it's good and more like floor() that round()
Do you think it makes sense, also for non-technical people?
 -  a lot but if you have 0.109, you round it to 1.11. then something cost 1.11 and you can't buy it because you only have 0.109 and you don't know it and people will not understand.

Do you find 0.1255 easier to read than 0.125501?
 - not personnaly
Should we kind of standardize the options (4, 6 and 8 digits) for all clients?
 - yeah, but with the floor function
I deliberately left the option of 2 digits out, because we're way past the "0.01 is equivalent to a penny/cent" era. Do you miss it still?
 - no it should in fact be set to worth 0.1 cent at all time and folow mtgox
Which option should be default?
- having a floor function witch floor to the 0.1 cent depending on the value of BTC

sry for english!

[jim618]

I think there are a few apps and websites that use the 'satoshi digits' to indicate the roll of the dice etc so you will always need the option to show all 8 digits.

I think most of the time people read the first 3 or 4 digits and then the other digits hardly even register in their visual cortex. Maybe we could have the first few digits in regular sized font and then the rest in a smaller font, like this:

0.12345678

big = 10pt, small = 7pt.
The cutoff for big-small would have to be an option.
That way there would not actually be any rounding, but you'd only notice the significant digits.

[jim618]

Here is a quick mock of what those "big-small" BTC amounts look like:



Current version on the left, big-small on the right. (big:small::10:7)

[Zeilap]

I think there are a few apps and website that use the 'satoshi digits' to indicate the roll of the dice etc so you will always need the option to show all 8 digits.

I think most of the time people read the first 3 or 4 digits and then the other digits hardly even register in their visual cortex. Maybe we could have the first few digits in regular sized font and then the rest in a smaller font, like this:

0.12345678

big = 10pt, small = 7pt.
The cutoff for big/small would have to be an option.
That way there would not actually be any rounding, but you'd only notice the significant digits.

I think this is what the blockchain.info phone app does. I liked the idea when I saw it, but it looked kind of weird to me. In a similar vein to changing font size, changing the colour saturation might also work, e.g.

0.12345678

or both combined (now my favourite after clicking preview)?

0.12345678

[Andreas Schildbach]

I think there are a few apps and website that use the 'satoshi digits' to indicate the roll of the dice etc so you will always need the option to show all 8 digits.

I think most of the time people read the first 3 or 4 digits and then the other digits hardly even register in their visual cortex. Maybe we could have the first few digits in regular sized font and then the rest in a smaller font, like this:

0.12345678

big = 10pt, small = 7pt.
The cutoff for big/small would have to be an option.
That way there would not actually be any rounding, but you'd only notice the significant digits.

I think this is what the blockchain.info phone app does. I liked the idea when I saw it, but it looked kind of weird to me. In a similar vein to changing font size, changing the colour saturation might also work, e.g.

0.12345678

or both combined (now my favourite after clicking preview)?

0.12345678

Thanks for the suggestions. Bitcoin Wallet already has a highlight exactly like this: 0.12345678, the blockchain.info app just forked from Bitcoin Wallet...

The interesting info is that people seem to prefer floor to round, I would have never expected this. Any opinions towards round?

[jim618]

I think floor is superior to round as you always want to know 'Do I have enough money ?"

If you show amount = floor(total) then you have at least that amount to spend, whereas with round you aren't sure if you can afford the amount shown.

[Andreas Schildbach]

I think floor is superior to round as you always want to know 'Do I have enough money ?"

If you show amount = floor(total) then you have at least that amount to spend, whereas with round you aren't sure if you can afford the amount shown.

Ok, for the wallet balance this seems reasonable. Does the same logic apply to payments sent and payments received (transactions list)?

[jim618]

No I don't think so.

For the currency conversions in MultiBit I use round-even when displaying the equivalent currency amount.

If I was going to round the BTC I'd probably use round-even too. If it is 1.99999999 you'd want to show it as "2.00000" say rather than "1.99999".

It means if you add up the rounded amounts you won't get the total balance but rounding is lossy so you cannot expect it to be the same.

[nwbitcoin]

This is going to be a huge problem for mainstream uptake of bitcoin.

The way that bitcoin is deflating against fiat currencies means that very soon a single BTC is going to be useless for day to day use.  This means that there are going to be a lot of zeros and points in funny places if we carry on with the current system.

Maybe we need to start looking at this from the other side of the decimal point.

Maybe its time to consider that the unit of interest to the public should be the Satoshi.

A Big Mac would cost 0.12345678 bitcoins, but that too complex.  Its still too big, and with the public being used to 5 numbers as a maximum while out shopping, it would make sense to carry on the tradition.

What if it cost 12345678 Satoshi and forget the decimal?

From a commercial angle, why not call it 12.34 Mega Satoshis.  As inflation kicks in and a Big Mac costs 0.00123456, this will become 123 000 Satoshi but that could be in time for the mainstream takeup.

I know that on face value, this looks to be going against the grain, but in the grand scheme of things, the public needs as little difference to their fiat currency as possible. Having a figure which is a fraction of a fraction is really hard work to compare with a positive number in the 10s or hundreds.

From the wallet perspective, it should make no difference, its just how its presented.

Would love some feedback on this idea!

[solomon]

words

This dawned on me a few weeks ago, and i agree. It's both less practical and makes the transition much harder for those new to bitcoin when things are being bought and sold for 0.00xxxxxx.
I think  it would aid bitcoin to have figures in the range of other currencies that people are used to. It's quite alien to most people exchanging decimal amounts of anything. I think it will be more of a hurdle psycologically for newcomers to trade in what they consider a decent amount in fiat and 'only' receive a few decimals.

I think the easiest way is to normalise the use of mBTC in stores and exchanges, although it may cause some confusion, i'm not sure. Maybe Sato's is better

[dree12]

This is going to be a huge problem for mainstream uptake of bitcoin.

The way that bitcoin is deflating against fiat currencies means that very soon a single BTC is going to be useless for day to day use.  This means that there are going to be a lot of zeros and points in funny places if we carry on with the current system.

Maybe we need to start looking at this from the other side of the decimal point.

Maybe its time to consider that the unit of interest to the public should be the Satoshi.

A Big Mac would cost 0.12345678 bitcoins, but that too complex.  Its still too big, and with the public being used to 5 numbers as a maximum while out shopping, it would make sense to carry on the tradition.

What if it cost 12345678 Satoshi and forget the decimal?

From a commercial angle, why not call it 12.34 Mega Satoshis.  As inflation kicks in and a Big Mac costs 0.00123456, this will become 123 000 Satoshi but that could be in time for the mainstream takeup.

I know that on face value, this looks to be going against the grain, but in the grand scheme of things, the public needs as little difference to their fiat currency as possible. Having a figure which is a fraction of a fraction is really hard work to compare with a positive number in the 10s or hundreds.

From the wallet perspective, it should make no difference, its just how its presented.

Would love some feedback on this idea!

A satoshi won't be the smallest for long. We should use the nBTC (nanobitcoin) as the base unit, so that we can maintain the current BTC unit as simply bitcoin and go down from there.

[solex]

This is going to be a huge problem for mainstream uptake of bitcoin.

The way that bitcoin is deflating against fiat currencies means that very soon a single BTC is going to be useless for day to day use.  This means that there are going to be a lot of zeros and points in funny places if we carry on with the current system.

Maybe we need to start looking at this from the other side of the decimal point.

Maybe its time to consider that the unit of interest to the public should be the Satoshi.

A Big Mac would cost 0.12345678 bitcoins, but that too complex.  Its still too big, and with the public being used to 5 numbers as a maximum while out shopping, it would make sense to carry on the tradition.

What if it cost 12345678 Satoshi and forget the decimal?

From a commercial angle, why not call it 12.34 Mega Satoshis.  As inflation kicks in and a Big Mac costs 0.00123456, this will become 123 000 Satoshi but that could be in time for the mainstream takeup.

I know that on face value, this looks to be going against the grain, but in the grand scheme of things, the public needs as little difference to their fiat currency as possible. Having a figure which is a fraction of a fraction is really hard work to compare with a positive number in the 10s or hundreds.

From the wallet perspective, it should make no difference, its just how its presented.

Would love some feedback on this idea!

nwbitcoin, +1 for thinking through detail that most people just ignore.

For a while now I have been thinking that the twin Bitcoin "features" of many decimal places and serious deflation will be a real road-block to widespread casual adoption. People need to be able to quickly compare and absorb prices. How to do it?

The answer is by using existing fiat values. So, what is needed is a new type of "virtual fiat" wallet, call it the VF-Wallet and similarly for clients, a VF-Client.

What these do is allow users to select from a multi-choice the fiat they are used to, then it displays all the price values in fiat. However, no real fiat is involved. The actual transaction takes place entirely in Bitcoin with an fx rate determined by a weighted average of the main Bitcoin exchanges last execution price.

Merchants making many transactions would average out on the fx rate they receive.

[nwbitcoin]

This is going to be a huge problem for mainstream uptake of bitcoin.

The way that bitcoin is deflating against fiat currencies means that very soon a single BTC is going to be useless for day to day use.  This means that there are going to be a lot of zeros and points in funny places if we carry on with the current system.

Maybe we need to start looking at this from the other side of the decimal point.

Maybe its time to consider that the unit of interest to the public should be the Satoshi.

A Big Mac would cost 0.12345678 bitcoins, but that too complex.  Its still too big, and with the public being used to 5 numbers as a maximum while out shopping, it would make sense to carry on the tradition.

What if it cost 12345678 Satoshi and forget the decimal?

From a commercial angle, why not call it 12.34 Mega Satoshis.  As inflation kicks in and a Big Mac costs 0.00123456, this will become 123 000 Satoshi but that could be in time for the mainstream takeup.

I know that on face value, this looks to be going against the grain, but in the grand scheme of things, the public needs as little difference to their fiat currency as possible. Having a figure which is a fraction of a fraction is really hard work to compare with a positive number in the 10s or hundreds.

From the wallet perspective, it should make no difference, its just how its presented.

Would love some feedback on this idea!

nwbitcoin, +1 for thinking through detail that most people just ignore.

For a while now I have been thinking that the twin Bitcoin "features" of many decimal places and serious deflation will be a real road-block to widespread casual adoption. People need to be able to quickly compare and absorb prices. How to do it?

The answer is by using existing fiat values. So, what is needed is a new type of "virtual fiat" wallet, call it the VF-Wallet and similarly for clients, a VF-Client.

What these do is allow users to select from a multi-choice the fiat they are used to, then it displays all the price values in fiat. However, no real fiat is involved. The actual transaction takes place entirely in Bitcoin with an fx rate determined by a weighted average of the main Bitcoin exchanges last execution price.

Merchants making many transactions would average out on the fx rate they receive.

Yes, that is the answer!

If everyone is carrying a simple exchange in their pockets, then while their minds are spending Dollars, Pounds, Yen or Euros, they are really spending bitcoins where that is the cheapest option. 
If you think of it like the way the telephone network was derestricted, and people could choose to use voip or traditional pbx.  The only thing they actually cared about was talking to Aunt Bessie for the least cost.  That is what this wallet would allow.

Use bitcoins to make stuff cheaper by using a virtual fiat wallet!

You want mainstream take up?  This might be how we are going to convince people to try it out!

[solex]

This is going to be a huge problem for mainstream uptake of bitcoin.

The way that bitcoin is deflating against fiat currencies means that very soon a single BTC is going to be useless for day to day use.  This means that there are going to be a lot of zeros and points in funny places if we carry on with the current system.

Maybe we need to start looking at this from the other side of the decimal point.

Maybe its time to consider that the unit of interest to the public should be the Satoshi.

A Big Mac would cost 0.12345678 bitcoins, but that too complex.  Its still too big, and with the public being used to 5 numbers as a maximum while out shopping, it would make sense to carry on the tradition.

What if it cost 12345678 Satoshi and forget the decimal?

From a commercial angle, why not call it 12.34 Mega Satoshis.  As inflation kicks in and a Big Mac costs 0.00123456, this will become 123 000 Satoshi but that could be in time for the mainstream takeup.

I know that on face value, this looks to be going against the grain, but in the grand scheme of things, the public needs as little difference to their fiat currency as possible. Having a figure which is a fraction of a fraction is really hard work to compare with a positive number in the 10s or hundreds.

From the wallet perspective, it should make no difference, its just how its presented.

Would love some feedback on this idea!

nwbitcoin, +1 for thinking through detail that most people just ignore.

For a while now I have been thinking that the twin Bitcoin "features" of many decimal places and serious deflation will be a real road-block to widespread casual adoption. People need to be able to quickly compare and absorb prices. How to do it?

The answer is by using existing fiat values. So, what is needed is a new type of "virtual fiat" wallet, call it the VF-Wallet and similarly for clients, a VF-Client.

What these do is allow users to select from a multi-choice the fiat they are used to, then it displays all the price values in fiat. However, no real fiat is involved. The actual transaction takes place entirely in Bitcoin with an fx rate determined by a weighted average of the main Bitcoin exchanges last execution price.

Merchants making many transactions would average out on the fx rate they receive.

Yes, that is the answer!

If everyone is carrying a simple exchange in their pockets, then while their minds are spending Dollars, Pounds, Yen or Euros, they are really spending bitcoins where that is the cheapest option.  
If you think of it like the way the telephone network was derestricted, and people could choose to use voip or traditional pbx.  The only thing they actually cared about was talking to Aunt Bessie for the least cost.  That is what this wallet would allow.

Use bitcoins to make stuff cheaper by using a virtual fiat wallet!

You want mainstream take up?  This might be how we are going to convince people to try it out!

Agreed!  This could be the Bitcoin fiat-killer app which takes the mainstream by storm. I was going to do a fancy new post announcing the VF-Wallet/Client idea, with a bit of background and collaborative input.  Been distracted lately instead hammering on about two much more pressing issues which need to be addressed first: the 1Mb max block size, and the lack of an ISO code for Bitcoin. No good taking it mainstream when it is simply not up to the job.

[Sukrim]

Even with (compared to BTC nearly static) fiat currencies this would cause a LOT of uproar. Just download a year worth of Forex data and then act as if your USD account displayed its values in EUR instead (or the other way round). Suddenly your balance is different every minute, you cannot tell how much you'll earn and spend any more until you actually do so...

[solex]

Even with (compared to BTC nearly static) fiat currencies this would cause a LOT of uproar. Just download a year worth of Forex data and then act as if your USD account displayed its values in EUR instead (or the other way round). Suddenly your balance is different every minute, you cannot tell how much you'll earn and spend any more until you actually do so...

Sukrim, step back and think about it further. If you transfer money from euros or dollars into bitcoin and use it to buy an item off a website in bitcoin then you would be paying more or less in fiat terms by the time you do the purchase. Probably more, with bitcoin rising so much. Are merchants going to revise their Bitcoin prices (usually downward) every minute, hour or even daily?

During the transition period when merchant costs are in fiat, they will be thinking of pricing in fiat terms. It is a hassle to keep revising their prices downwards as bitcoin appreciates. Stale bitcoin prices will always be seen by the public as too expensive.

Making bitcoin a less visible layer underneath a virtual fiat transaction is the way to go. Yes, VF wallets will jump around in value, but if you have $200 worth in fiat and it oscillates between $190 and $210 every now and again, so what? it is not unusable for buying a $10 book.

[nwbitcoin]

Even with (compared to BTC nearly static) fiat currencies this would cause a LOT of uproar. Just download a year worth of Forex data and then act as if your USD account displayed its values in EUR instead (or the other way round). Suddenly your balance is different every minute, you cannot tell how much you'll earn and spend any more until you actually do so...

Sukrim, step back and think about it further. If you transfer money from euros or dollars into bitcoin and use it to buy an item off a website in bitcoin then you would be paying more or less in fiat terms by the time you do the purchase. Probably more, with bitcoin rising so much. Are merchants going to revise their Bitcoin prices (usually downward) every minute, hour or even daily?

During the transition period when merchant costs are in fiat, they will be thinking of pricing in fiat terms. It is a hassle to keep revising their prices downwards as bitcoin appreciates. Stale bitcoin prices will always be seen by the public as too expensive.

Making bitcoin a less visible layer underneath a virtual fiat transaction is the way to go. Yes, VF wallets will jump around in value, but if you have $200 worth in fiat and it oscillates between $190 and $210 every now and again, so what? it is not unusable for buying a $10 book.

Finally, someone on this forum is thinking like a user rather than a developer!

Currently, this issue of the value of bitcoins to other fiat is why nobody is spending any bitcoins.  I am setting up an ecommerce site at the moment, and am having exactly the problems you are describing.  The only solution I can think of is to offer the bitcoin price only once I'm through checkout on the total spent.

If a bitcoin wallet did this automatically, it would make life very easy, and save me 5%+ on Paypal charges.  More importantly, my customer would be using bitcoins without having to think about conversion prices etc.

I think we may have stumbled on to something very good here!

[poly]

There is also using coin dust as an identification / data passing method, such as what is used by MPEx. I don't suggest rounding it off on large screens (ie desktop, tablets), but for mobile devices rounding wouldn't be a bad idea.

[Sukrim]

Well, then do it.

Sorry, but the only real way to see how users are going to react ("I bought 200 USD of these 'Bitcoins' and now the USD value in my software jumps!") is to try it out. I personally think it will be a horrible user experience (especially in a moving market and then especially in a downward moving market!) and interestingly these ideas often come up in this forum during rally periods, not during "recessions" in BTCUSD prices.

To display prices in BTC there are easy ways, for example update a general conversion number every hour or so and state that the final price will be calculated + displayed at checkout, including shipping, taxes and whatnot. Also you can just give higher estimates in prices (I guess your goods will be priced in USD) and promise that at checkout the price will be the same or less. With such unstable conversion rates, it is hard anyways to get "used to" any kind of BTC price - a few months ago a BTC bought a single cheap meal at McD, now it can buy a quite nice candle light dinner for 2 and who knows what it'll buy in 2 months from now. It's not like customers are used to seeing prices in BTC and immediately think "wow, this is cheap" without calculating the USD price anyways.

The topic is still how to overcome the problem, that 1 BTC is now not something that's easily spent in dozens any more and how to solve display issues to make it still "processable" for humans (it is hard to see + immediately know a price if it has a bunch of 0s in it).

So far solitions include:
* Move the decimal seperator (e.g. 1 BTC = 1000 mBTC), because it is easier for humans to process large numbers, they espect max. 2 digits after the decimal seperator for currencies and thousands are often grouped, making it more legible.
* Round to the nearest X decimals, because even though it is not an exact value, it makes it easier to process and read and most transactions might not be about spending everything down to the last satoshi.
* Use the floor function instead of rounding (and maybe display the omitted decimals in smaller script and/or colour), this makes sure you can definitely spend everything that is displayed while still keeping the decimals at a comfortable level.
* Display the balance in a different currency alltogether, because users will spend most BTC for things priced in USD anyways and it makes transitioning as well as usage easier if you have already some well known and common elements in place.
* Do nothing, everything is fine and maybe BTC crashes anyways, so the problem is only temporary.