Getting the "Current" ROI at the moment you have.

[NinjaBits]

Hello. I am coding a project, where I must programatically determine how much ROI (Return of Investment) you have reached every day.
I just need the correct formula, not the code

For example:

Investment: 0.1 BTC
Daily Percent: 2.4%
Days: 4
Current ROI:

OR

Investment: 0.25 BTC
Daily Percent: 2.4%
Days: 18
Current ROI:

Currently what I managed to come up is:

Code:

<?
$investment = 0.10;
$percent = 2.4;
$days = 10;
$earned = $investment + $days;
$ROI = ($investment * $earned) / 100;
?>

This formula gives me that ROI is: 0.1001% which can not be right. I would really appreciate for some1 to reveal the formula to calculate this (plain, not in code necesserally).

[buwaytress]

Not sure what you're really asking for but ROI in your examples is simply gained by multiplying the daily  interest rate by the number of days.

So for eg. 1, ROI(%) is "daily interest" * "no.of days".
ie. 2.4*4 = 9.6%
The ROI expressed in bitcoin is 0.1*9.6/100

[NinjaBits]

Not sure what you're really asking for but ROI in your examples is simply gained by multiplying the daily  interest rate by the number of days.

So for eg. 1, ROI(%) is "daily interest" * "no.of days".
ie. 2.4*4 = 9.6%
The ROI expressed in bitcoin is 0.1*9.6/100

Thank you for the answer.