Well I don't think its that simple, what I've done is X12 to get the yearly salary, then subtract the �4745 personal allowance that's tax free. Then the next 1960 is taxed at 10% or �196 in tax. Then up to �30,500 is taxed at 22% anything above is taxed at 40%. Then subtract the tax payable from your annual total, divide this fiqure by 12 and voila you have your monthly net income. Bit of a stammash but it should work out, peobably an easier way somehow, but this should be correct. Good luck!