UK Retirement Planner — Monte Carlo Simulation
See your true retirement odds — not a single optimistic line. ODOpt runs thousands of simulated futures across different markets, inflation paths and drawdown strategies, with UK tax handled throughout.
Free to use · No sign-up · Runs in your browser
Retirement planning with real probabilities
Most calculators show one straight line based on an average return you'll never actually experience. Real markets rise and fall in an order you can't predict — and that sequence matters enormously in retirement. ODOpt runs thousands of Monte Carlo simulations so you can see the range of outcomes and how likely your plan is to last.
Model multiple pots (pensions, ISAs and general accounts), asset allocation and glidepaths, contributions, spending, guaranteed income, and tax-optimised withdrawals — then stress test against crises to see how your plan holds up.
Monte Carlo simulation
Thousands of simulated market paths reveal the full range of outcomes, not an average.
Tax-optimised drawdown
Withdrawals modelled across pensions, ISAs and general accounts with UK tax applied.
Multi-asset portfolios
Set asset allocation and a glidepath that shifts over your horizon.
Crisis stress testing
See how your plan copes with market crashes and poor sequences of returns.
How it works
- Describe your situationAge, horizon, pots and balances, and your asset allocation.
- Set contributions & spendingAdd contributions, planned spending, and any guaranteed income.
- Run the simulationRead the fan chart, success rate, drawdown and tax to judge your plan.
Frequently asked questions
What is Monte Carlo retirement planning?
It runs your plan through thousands of possible market sequences instead of a single average return, so you see a realistic range of outcomes and how often your money lasts.
Does it model UK tax on withdrawals?
Yes. Drawdown is modelled across pensions, ISAs and general accounts with UK tax applied, so the numbers reflect what you actually keep.
Is the Retirement Planner free?
Yes — every ODOpt tool is free to use with no sign-up. You can go ad-free with an optional subscription.
Related tools
See your real retirement odds
Free to use, no sign-up. Go ad-free any time.
Open the Retirement Planner — free