[zec] calculator dont giving same results ???

Hi friends , did someone know which calculator is close to reality ? why difficulty is not the same ...

with same stats :
coinwarz give around 1800$ profit when cryptocompare give ~ 1250$
i m on ethereum most time , but wondering why calculator are not giving serious stats ...

at worst i will mine 24h to see which one is close to reality

have a nice day

regards