Model how a pension pot might hold up in retirement under a fixed growth assumption or a Monte Carlo spread of market outcomes. Every input is editable — this is a planning sketch, not advice.
Last updated: 27 Aug 2026, 18:39 BST
Not financial advice — an illustrative planning sketch only, not a regulated recommendation; speak to a regulated financial adviser or use MoneyHelper's free guidance before deciding anything.
Your data stays private — everything runs in your own browser, nothing is uploaded or sent anywhere, and nothing is remembered once you close this tab unless you use "Save inputs…" (top right) to download a copy you can reopen later with "Load inputs…".
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Answer a few plain-English questions about your household and we'll set up the plan below for you — no jargon, no spreadsheet required.
Guided setup
Your privacy: this planner runs entirely in your own browser — nothing you type here is sent anywhere, saved to any server, or seen by anyone else, including us. Close this tab without saving and it's gone for good. Use "Save my answers" at the end to download a spreadsheet you keep on your own device, so you can pick this up again later.
Your plan is built
Your answers have been used to set up the Household plan below — scroll down to see the full results, or switch to "Simple view" above for a plain-English summary. Everything is still editable in Detailed view if you'd like to refine it.
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A plain-English summary of your joint plan. Everything else stays exactly as set in the Detailed view — these match its "Viewing" mode, inflation and your SIPP return so you can adjust the big-picture assumptions without switching back and forth. Fixed growth updates live; Monte Carlo and the stress tests need "Refresh".
Your money over time
Where your income comes from
Each shaded band is one source of household income, stacked by year. Based on steady, typical-average growth throughout — not a range of outcomes.
Each band shows how much of that year's spending came from that source, not the gross amount received or withdrawn. One-off large expenses and their funding are excluded — they're a capital cost, not ongoing income.
What would change this most (under steady growth)
This is an illustrative projection only, built from the assumptions currently entered in the Detailed view — it is not financial advice, and this isn't a regulated financial planning tool. Speak to a regulated financial adviser or use MoneyHelper's free guidance before making retirement decisions. Everything stays on this device — nothing is uploaded anywhere, and nothing is saved automatically, so use "Save inputs…" in Detailed view to keep a copy for next time.
Pot & timeline
Withdrawal strategy
Gilt ladder funding
Growth model
State Pension & tax
Household — people & spending
Household — existing savings
Emergency fund & other savings
Annuity purchase
One-off windfall
One-off large expenses (household mode) Up to three one-time costs — a roof repair, a new car, a wedding — each landing once on the date you give it. Entered in today's £ and inflated to that date like everything else. Each is funded, in order, from: your other savings (both of you, combined), then your GIA, then your ISA, then your SIPP (paying whatever income tax that draw actually triggers) — whichever tier still has money left when the previous one runs out. Split between the two of you the same way as the "drawn down together" setting above governs the normal shortfall waterfall: one of you first, then the other, or evenly, split within each tier. The emergency fund is never touched. If every tier runs dry before the cost is covered, the shortfall is treated as a failure of the plan for that year, the same as failing to meet your normal income need. Untick "Include this expense" to switch a slot off without losing what you've typed in — it's then ignored completely, the same as leaving its amount at £0.
Defined benefit pensions Add any final-salary / DB pensions either of you has. Each is assumed index-linked (CPI) and starts paying from the date you set — on top of the State Pension above. Useful if a DB pension is technically available now but you're deliberately delaying it — just set its start date to whenever you actually plan to take it.
Other income & dividends "Other income" covers anything not already captured above — e.g. self-employment (enter the net figure), taxed as ordinary income like a DB pension. Blank start/end age = from now / for the rest of the plan. "Dividend income" is taxed separately under dividend tax rules and continues for that person's life. Neither grows with inflation by default — each has its own growth-rate field.
Non-earner pension contributions UK rules let anyone under 75 contribute up to £3,600 gross (£2,880 net) to a pension each tax year with basic-rate relief, even with no earnings. Tick to have both of you pay the net amount into your own SIPP every year from that date. The net cost is added to your target spending (funded through the normal waterfall), while the gross, topped-up amount lands in the SIPP. Stops at 75 or death.
Additional recurring expense (household mode) An ongoing monthly cost — e.g. supporting a relative with living expenses — added to your required household net income from the date you set, for as long as it's ticked on. Entered in today's £ per month and inflated each year the same way your target income is. Unlike the one-off expenses above, this is an ongoing need funded through the normal income waterfall (SIPP/ISA/GIA/ladder), not a lump sum, and it is not reduced by the survivor-spending % after the first of you dies — it keeps going in full until you untick it (there's currently no separate end date). Untick "Include this expense" to switch it off without losing what you've typed in.
Drawdown order Each year, in order: 1) live off the maturing gilt-ladder rung; 2) State Pension and any DB pensions land as cash, then draw each SIPP up to the top of the basic-rate band, which buys the next ladder rung; 3) any leftover funds both ISA allowances, topping up from the GIA if needed. If that's not enough: draw the GIA, then the ISAs, then SIPPs beyond the basic rate (40%+ tax), then other savings. The emergency fund is never touched.
Historical stress test Replays your plan's opening years against a real, curated UK market episode instead of your assumed average return — a check on how this exact plan (ladder included) would have held up in a genuine historical shock, rather than a randomly-generated one. Only the growth portfolio's return and inflation are overridden, for that scenario's own years; everything reverts to your normal assumptions immediately afterwards. Some figures for these years (noted in the results) are estimated rather than found in a published source — see the results and methodology notes for exactly which.
Goal seek: what income, retirement age, or pot size works? Two different calculation methods, picked below — everything under this toggle switches together, so you're never mixing the two by accident. Fixed growth: based on Fixed mode's single assumed-average-return path (not a worst case), asking what income this plan could sustain without ever falling short. Monte Carlo: based on a full spread of randomly-simulated outcomes, letting you target a chosen failure rate directly instead of a single average path — a figure that looks sustainable under Fixed growth can still fail in a large share of Monte Carlo's simulations at the same income, so Monte Carlo is the more realistic check of the two. This is separate from the Historical stress test card above, which replays one specific real past market episode rather than searching for a number.
Single assumed-average-return path — fast, but blind to how much market ups and downs along the way could throw the plan off.
Fixed-growth mode updates live. Monte Carlo runs on demand.
Fixed growth updates live as you change inputs — Monte Carlo only updates when you click "Run simulation" (it's too heavy to re-run on every keystroke). The stress-test options replay your plan's opening years against a real historical UK market episode instead — household mode only.
Export summary Exports whatever's currently shown above (Fixed, Monte Carlo, or a stress test) — headline results, your key assumptions, and a condensed year-by-year table. Excel also includes the full detailed table as a second sheet.PDF opens your browser's print dialog — choose "Save as PDF" as the destination.
Pension pot over time
Nominal vs. today's-£ (real) pot value each year.
Each pot over time
Click a pot below to show/hide it — see which runs dry first, and when.
Where your income comes from
Each shaded band is one source of household income, stacked by year. Based on steady, typical-average growth throughout — not a range of outcomes.
Each band shows how much of that year's spending came from that source — not the gross amount received or withdrawn (a SIPP withdrawal, in particular, is very often bigger than what's needed for spending, with the rest swept into the ISAs/GIA; only the spending share is shown here, wherever in the drawdown order it happens). GIA/ISA/other savings only appear here for money actually spent from them once other sources run out — not the routine GIA-to-ISA sweep or bed-and-ISA harvest, which move money around rather than spend it. One-off large expenses and their funding are deliberately excluded — they're a capital cost, not ongoing income.
Methodology & assumptions
This tool produces an illustrative projection only, built from the assumptions you enter — it is not financial advice, and neither this tool nor its author is a regulated financial adviser. It takes no account of your full circumstances; real investment returns are unpredictable, tax rules change, and past performance is not a guide to the future. Speak to a regulated financial adviser or use MoneyHelper's free guidance before making retirement decisions.
Your data stays private: this runs entirely in your own browser, with nothing uploaded, sent anywhere, or seen by anyone else — including whoever shared this file with you. Nothing is remembered once you close the tab, either, so use "Save inputs…" (top right) to download a copy of your answers you can reopen with "Load inputs…" next time.