How the calculators work
A quick tour of what each tool does and how they fit together — nothing here tells you what to do with your money, it's just an explanation of what you're looking at.
Every number on this site comes from you. There are no defaults pretending to be recommendations, no pre-filled "typical" figures dressed up as guidance — just fields you fill in, and maths that runs on exactly what you've entered. Change a number, the projection changes with it. Leave something blank, it's treated as zero.
The only things we supply are the shared UK assumptions — interest rates, inflation, growth rates — and even those are just a starting point you can override with your own figures at any time (see UK Rates below). This page is a description of what each tool does, not a suggestion for what your numbers should be — for that, see our Terms & Conditions on why we're not the right people to ask.
Getting started
Income & Basic Info
The starting point for everything else. Your age, target retirement age, salary and any bonus or allowances live here — every other calculator reads your age and retirement age from this one place, so you only need to enter them once.
Open Income & Basic InfoPensions
Workplace Pension
Projects your workplace pension pot from today to retirement, based on your own contribution rate, your employer's contribution rate, and how you'd like it drawn down once you get there.
Open Workplace PensionFinal Salary (DB) Pension
For defined benefit schemes — NHS, Local Government, Teachers, Civil Service and similar. Lets you pick a scheme preset to fill in typical rules, or set everything manually if yours works differently.
Open Final Salary (DB) PensionSIPP Calculator
Self-Invested Personal Pensions work a little differently to tax relief — this models your own contributions, the tax relief HMRC adds automatically, and what income the pot could provide later.
Open SIPP CalculatorState Pension
Based on your National Insurance qualifying years — enter how many you've built up so far, and it projects the rest based on your working years remaining.
Open State PensionISAs & Savings
Stocks & Shares ISA
Tax-free investment growth, tracked against the annual ISA allowance. You set the starting balance, monthly contribution, and how long you plan to keep contributing.
Open Stocks & Shares ISALifetime ISA
Works like the Stocks & Shares ISA, but adds the 25% government bonus on top of whatever you contribute — up to the LISA's own annual limit, which is lower than a standard ISA's.
Open Lifetime ISACash ISA
The same idea as the Stocks & Shares ISA, but for cash rather than investments — no market risk, and the growth rate you enter reflects savings interest rather than investment returns.
Open Cash ISACash Savings
For money outside any ISA wrapper. The one meaningful difference from a Cash ISA: interest here is taxable, so this calculator applies your Personal Savings Allowance automatically.
Open Cash SavingsProperty
Mortgage Calculator
Projects your mortgage balance and interest over time, and lets you model overpayments — a flat monthly amount, a schedule that changes over time, or one-off lump sums at specific dates.
Open Mortgage CalculatorHelp to Buy
If you have a Help to Buy equity loan, this tracks how the amount you owe changes as your property value changes, and models a few different ways you might choose to repay it.
Open Help to BuyThe engine room
UK Rates
Every calculator above draws its growth, interest and inflation assumptions from here. Pick a Conservative, Current Market, or Optimistic scenario, or override any individual rate with your own figure — the change applies everywhere at once.
Open UK RatesBringing it together
Financial Summary
Pulls together whatever you've entered across every calculator into one combined view — total projected net worth, retirement income from all sources, and how it all changes year by year. It only reflects calculators you've actually visited and filled in; anything you haven't gotten to yet just won't be included until you do.
Open Financial SummaryWant a suggested order to go through these in?
If you'd rather follow a step-by-step route through a specific goal — retirement planning, buying a first home, or comparing the three ISA types — rather than browsing the calculators in any order, there are guides for each.
Retirement Planning: A WalkthroughFirst-Time Buyer's Guide
Cash vs Stocks & Shares vs Lifetime ISA
Everything above is a description of what the tools do, not a recommendation for what to enter into them. The figures you use, the scenarios you pick, and what you do with the results are entirely up to you — see our Terms & Conditions for the full detail, and our Privacy Policy for how (little) data any of this involves.