Tell us about your situation
Enter your pension pot, ISA savings, salary, State Pension estimate, and what you want to spend in retirement. Takes about 5 minutes.
All data stays in your browser — nothing is sent to our servers.
Free · UK-specific · No product bias
Find out honestly whether
your retirement will survive.
Selvox runs 10,000 simulations of your retirement using 125 years of UK market data. You get a survival probability — not a misleading single projection.
- No email required
- Your data never leaves your browser
- No product recommendations mid-calculation
How Selvox works
Three steps. No jargon. No signup.
We run 10,000 simulations
Our engine samples from 125 years of UK market history, applying accurate UK tax rules to your specific situation in each simulation.
Uses block bootstrapping to model sequence-of-returns risk — the biggest threat to early retirees.
You get honest probability outputs
Instead of a single misleading figure, you see a survival probability and a range of outcomes — from the worst historical periods to the best.
73% survival probability means 7,300 of your 10,000 simulated futures still had money at your target age.
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Most comprehensiveFull Monte Carlo simulation. 10,000 scenarios. Your personalised survival probability based on your actual numbers.
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In-depth articles written for people who take their finances seriously
Should I Overpay My Mortgage or Invest? A UK Guide (With Calculator)
If your mortgage rate is above 4-5%, overpaying usually wins. Below that, investing has historically come out ahead. Here's how to work out the right answer for your situation.
12 · Apr 2026
ISA vs SIPP: Which Should You Prioritise in Your 40s?
A data-driven guide to choosing between ISA and SIPP contributions for UK investors in their 40s, with personalised tax analysis and a lifetime saving calculator.
11 · Mar 2026
The £100k Salary Trap: How to Protect Your Personal Allowance
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Built for UK investors. Validated against official sources.
years of UK market data
Barclays Equity Gilt Study (1899–2024), ONS inflation series, and JST Macrohistory Database. Not US data. Not a global average. Actual UK market history.
unit tests on the tax engine
Income tax calculations validated against HMRC's own PAYE calculator. State Pension projections validated against the DWP forecast service.
bytes of your data sent to our servers
Every calculation runs in your browser using a Web Worker. Your pension pot, salary, and savings figures never leave your device.
Built with feedback from the UK FIRE and personal finance community. Methodology open for scrutiny — if you find an error, we want to know.
See our data sources →Ready to find out where you actually stand?
5 minutes. No signup. No email required. Your data stays in your browser.
Start your retirement plan →Free forever. No credit card. No premium tier for the core calculator.
Selvox provides financial guidance only, not regulated financial advice. Always consult a qualified adviser for significant financial decisions.