Generally for a standard employee, the things they take out are straightforward and the tax/national insurance calculators will be accurate. The only other changes would be if you're on a pension plan with the employer, there will usually be a contribution from your gross pay as well as an employer contribution, but your employer will have to tell you how much it would be; in some pension schemes you can also choose to pay in extra to your pension, but obviously that will be under your control.
