Every assumption is visible and editable. The model runs entirely in your browser — nothing you type is sent anywhere, stored, or logged.
In today's money. The model increases it with inflation each year.
£12,548 is the full new State Pension. Most people get less — check your forecast.
Withdrawals are split between the two pots each year to keep the household's tax bill as low as possible — using both personal allowances before either of you pays a higher rate.
The new State Pension cannot be inherited. On first death the household permanently loses one State Pension and one personal allowance — but the bills don't halve.
…of the couple's income. 67% is the standard equivalence scale. Housing, heating and council tax barely move.
Tax-free cash spent elsewhere is not available to fund income later. In this model that changes the outcome more than any other single input.
Total value in today's money, including any tax-free cash still unspent. Tap or hover for the numbers.
The share of simulations in which the money lasted to your end age, at each level of income. The ring marks the income you set.
| Income after tax | Share of runs it lasted |
|---|
Nothing here is a fact. These are the numbers that decide the answer, so they belong to you, not to us.
5% nominal less 2% inflation = 2.94% a year after inflation.
The FCA prescribes returns but not volatility. This one is a guess — ours or yours, but a guess.
Most calculators never say which. Under one convention volatility lowers the compound return; under the other it does not. The two give different answers.
Frozen bands shrink in real terms every year — "fiscal drag". Current policy is a freeze, so 0 is the optimistic setting.
What is a pension stress test? A simulation that runs many possible futures for a pension pot in drawdown, year by year, to show how often the income lasts to your chosen age and what happens when it does not.
How long will my pension last? It depends on the pot size, income target, returns, tax and inflation. Enter your figures to see the share of simulations that fund the full income to your end age.
What return does it assume? By default the FCA's prescribed projection rates (COBS 13 Annex 2): 5% nominal less 2% inflation, giving about 2.94% a year after inflation. You can set your own.
Does it model UK income tax? Yes, for England/Wales/NI and Scotland. The basic-rate band is stacked on top of whatever personal allowance survives the £100,000 taper, which most calculators get wrong.
Does it model a couple? Yes. Two pots, two State Pensions and two personal allowances, with each year's withdrawal split between the pots to minimise the household tax bill.
Is this financial advice? No. It is not authorised or regulated by the FCA, gives no recommendation, and names no pension product, fund or provider.
What we found building this. The 4% rule is a fact about American data — run the same test on British market history and the equivalent figure is 3.77%. A stated return is two different numbers, and no consumer calculator says which. And one decision about tax-free cash moves the answer further than everything else combined. Read the findings →