UK financial planning tools

Which tool fits which question

The questions a payslip raises usually come down to four, and each has a different right tool. "What will I actually take home?" is the salary calculator, or the required-salary tool when you know the take-home you need and want the gross that produces it. "What does this change cost or save me?" is the comparison family: two salaries side by side, this year against last year, or a pay rise worked through to what actually reaches your account after the extra tax and any tapered allowance. "What happens if my pay stops or drops?" is the maternity and sick pay tool, which blends a reduced-pay period into a full year rather than pretending the year was normal. And "can I afford this?" is the borrowing set: mortgage affordability on lender income multiples, loan repayment, and the debt tools for what existing balances really cost to clear.

What the take-home tools share

One calculation engine sits under the tools that work out a year's pay: the same tax-year configuration, the same National Insurance basis and the same student-loan thresholds, so two of them given the same inputs cannot disagree with each other. The payslip checker works one pay period as payroll does, so it can differ from them by a pound or two. The borrowing and entitlement tools read their own rules (lender multiples, statutory rates, holiday law), each cited on its page. Every result is a planning estimate and not advice.

• No sign-in is needed for any calculator, and figures you type stay in your browser.
• Payroll timing and benefits in kind are outside the estimate. National Insurance is modelled on the standard employee basis only; non-standard NI category letters are not.
• If a result differs from your payslip, the payslip diagnostic works out what your pay and tax code should have produced and compares the payslip against it line by line, so you can see which line moved rather than guess which assumption was wrong.