PROFIT CALCULATOR

someone can tell me with profit calculator is more accurate?

http://burstcoin.biz/calculator for example is accurate.
They all use simple math and you could calculate your Burstearning per day by the following simple equation:
Burst_per_day = ( 24 x 60 x A x B ) / (4 x C)
Where
 A is the current Block reaward (this month it is 2919Burst, but this value decrease 5% each month!)
 B is your Plot size in TB
 C is the current Network size in TB
The problem is, that the Network size (C) is fluctuating between 300015000 within a few days the last weeks because of some problems with pools and forks. It makes it hard to calculate your earnings. I would recommend to calculate with a value between C=8000 and C=10000 for now.
Here you can get an idea how the value of C changed over the last time: http://burstcoin.biz/charts/estimatednetworksize