Income taxes

How accurate are the online tax home pay calculators, such as http://www.thesalarycalculator.co.uk/salary.php ?

Will those take home numbers really be my net, or are there other taxes usually taken out and not mentioned here (possibly any UK equivalent of state taxes and SUTA)? I'm trying to work up a budget to see if the salary I'm being offered will work for us, and getting the net pretty accurate is a big first step

Thanks!

The online calculators should be accurate - I just put in my salary and it gave me what i actually take home each month after taxes, NI and student loan.