I know we have 1 MB block size limit introduced into Bitcoin by Satoshi Nakamoto when using bitcoin.
this is mean we have max 1000 sat/b "1 MB" right?
No, there is no maximum fee rate. The fee rate is market-based. The block size limit means that standard transactions are limited to 1,000,000 bytes and Segwit transactions are limited to 4,000,000 bytes.
Satoshi/byte = the fee rate you are paying based on that limit. 1 Satoshi = 0.00000001 BTC. Median transaction size is 226 bytes. You can do the math.
Today, when I check my blockchain wallet, found this numbers.
Can anyone explain why I get this numbers?
Due to current congestion, regular transactions (not immediate confirmation) cost 820 satoshis/byte and priority transactions (next block) cost 1091 satoshis/byte according to Blockchain.info's fee algorithm. Personally, I'd prefer to pay
significantly less than that for confirmation within 24-72 hours. If you are willing to wait just 24 hours, you can pay closer to 200 satoshis/byte.