Retirement calculator

Two projections, one tax calculation

A retirement plan has two halves and they are computed separately, because they are different arithmetic. While you are paying in, the pot grows and the contributions compound. Once you retire, the pot is charged an income every period and shrinks — usually while still growing, which is why a pot can pay out more than it was worth. The two are joined at exactly one number: the balance on the day the first stops and the second starts. What the income then costs in tax is a third calculation, by a different engine, resting on a different kind of claim.

The pot, period by period

There is one loop and it is the only place money moves. For each period: add the contribution; apply the period’s growth; deduct the platform charge; take the withdrawal last. Every figure is a whole number of pence and every row satisfies opening + paid in + growth − charges − taken out = closing exactly, so the headline cannot disagree with the schedule it was read off. The table on the page shows one row a year, rolled up from the periods, and each annual row balances on the same identity.

In the second half the balance floors at zero. A withdrawal larger than the pot is truncated to what is there, and once a payment cannot be made in full the income stops for good — the page reports that year rather than the year the balance hits zero, because the first short payment is the one that matters to whoever is living on it.

“What do I need to save?” is three questions, answered backwards

The income you want, less any other retirement income once that has started, is what the pot has to pay — and the whole of it for any years before then. The smallest pot that pays it in full for the whole of retirement is found by searching: a pot is tried, the whole retirement is projected at it, and the search narrows to the penny where one more penny of income would not last the term. The contribution that reaches that pot is then solved the same way, against the saving projection. Every step re-runs the same loop, so the answer cannot drift from the schedule underneath it — and if a target cannot be reached at all, the page says so and gives the shortfall rather than quietly handing back the largest figure it tried.

The target is a gross income. Solving for a take-home figure would mean working backwards through an allowance that tapers, bands that differ by region, and rates that will not still be these rates when the income is drawn. The tax is shown separately instead.

Inflation and an inflation-linked income are different things

This page has two boxes that both mention rising prices and they do opposite jobs.

• Inflation restates finished answers in today’s money. The pot is divided by (1 + inflation)^years once, after the schedule is complete. It moves no balance, no income and no depletion year — it changes the units the answer is quoted in.
• Increasing the retirement income each year is a real cash flow. An income that rises with prices takes more money out of the pot every year, so the pot empties faster and the depletion year moves. Set it to your inflation assumption if you want an income that keeps its buying power.

They are deliberately not one control. If they were, ticking “show me today’s money” would silently empty the pot faster — an answer that changed depending on the units it was written in.

Why the State Pension is offered and never filled in

The State Pension is the largest line in most people’s retirement income, and leaving it out overstates what somebody needs to save. The published full rates now sit beside that box: they are in this site’s rules files, checked against gov.uk and dated like every other statutory figure here, and the page shows the weekly figure DWP publishes alongside the annual figure the box takes.

They are shown and they are not applied. The full rate is what a complete National Insurance record buys. Many people have fewer qualifying years and get less; a pre-2016 record can carry a protected payment and pay more; deferring pays more again. None of that is something this page asks about, so filling the figure in would tell some readers they need to save considerably less than they do — in the one direction a retirement calculator must never err — and it would look like a figure the site had worked out about them rather than a national headline rate.

So the box starts at zero, because zero asserts nothing, and it changes when you press the button or type your own number and at no other time. Nothing moves merely because the benchmark is on screen. It is also not the only thing that belongs in that box — a defined benefit pension, an annuity or a rental profit go in exactly the same place. Your own figure is on your State Pension forecast at gov.uk, which is the only thing that knows your record.

How long the money might have to last, and why there is no life expectancy

“Years the income has to last” is the one input on this page with nothing to anchor it. The optional panel in the breakdown is the anchor: on the Office for National Statistics’ latest projection, out of a hundred people your age today, how many are projected to reach seventy, eighty, ninety and beyond — and the ages three-quarters, half and a quarter of them are projected to reach.

It deliberately does not quote a life expectancy, and that is the whole design rather than an omission. Life expectancy is roughly the age half of a group outlives, so a pot built to last exactly that long runs out for one retiree in two — and it runs out for the half who lived longest, which is to say the half who needed it most. The third figure in that range, not the middle one, is the one worth planning against.

The figures are a projection about a population and not a statement about you. They describe everyone in the United Kingdom born the same year, and know nothing about your health, your job, your income or your family — differences wider than the difference between the two tables ONS publishes. Where its published projection stops, the panel shows nothing rather than carrying the last mortality rate forward. The panel is off until you ask for it, and switching it on changes no figure anywhere else on this page.

The projection makes an arithmetic claim, and no other

There is no statutory figure anywhere in the projection. The growth rates, the charge, the terms, the contribution and the income are all yours, and there is nothing in them an authority could confirm, because a growth assumption is not the sort of thing that can be correct. So that part carries no gov.uk verification claim and it will not borrow one from the tax section below. The claim it makes is arithmetic: given these inputs and the conventions above, the schedule is right and every figure is read off it.

A fixed-rate projection is not a forecast. Nothing grows at the same rate every period. Real returns arrive in an order, and the order changes the outcome — worst in the years either side of retirement, because an income taken during a bad run sells units that are not there to recover afterwards. Treat every figure about the pot as what a constant rate would have produced: useful for comparing two plans, poor for predicting a balance.

The tax on the income

Income from a pension is taxed as earned income in the year it is taken. It is not a separate charge with its own rates: it goes on top of everything else taxable you receive that year and is charged at whatever rates that income has already reached — which is why the other-income box changes the tax as well as the size of the pot you need. The tax attributable to the pot’s income is measured, the bill with it less the bill without it, rather than derived from a rate.

Two limits on that figure are larger here than on any other page of this site. It applies today’s published rates to an income starting years from now, and nobody knows what the bands will be by then; the calculator offers the tax years it holds rules files for and no others. And it taxes the whole of the income from the pot, where most people can normally take part of a defined contribution pot free of income tax — so it charges more tax, and leaves less to spend, than somebody taking tax-free cash would see. The pension drawdown calculator models that split, and the tax band by band, on a pot being drawn on now. No National Insurance is charged on a pension income, at any age, so none is shown.

Where the tax figures come from

• gov.uk — Income tax rates and allowances: current and past
• gov.uk — Tax when you get a pension
• gov.scot — Scottish income tax rates and bands

The income tax rates, thresholds and allowances this page calculates with were verified against gov.uk on 12 August 2026. That check covers the published figures used by the tax part of this page and nothing else. It does not verify any figure the page produces, and it does not reach the projection at all: the growth rates, the charge, the terms and the contribution have no published source to be checked against. The check was carried out automatically and no named person has signed it off. It also says nothing about whether those rates will still apply when you retire. Check anything that matters against gov.uk, or with an accountant or a regulated adviser.

What this calculator does not model

• Tax-free cash, and therefore the lump sum allowance that caps it. The whole of the income from the pot is taxed here.
• The annual allowance and the money purchase annual allowance, which cap what can go into a pension each year with tax relief. A contribution above them is not flagged. The pension drawdown calculator reports the money purchase allowance where it matters most.
• Tax relief on the way in. The contribution box is what actually lands in the pot, after relief. Enter what goes in, not what leaves your bank account.
• A contribution that rises with your pay, an employer that changes, a career break, or a lump sum arriving part way through. The contribution is level for the whole term.
• Anything about you. No life expectancy, no health, no partner, no other savings, no care costs, no state pension age, no property. This is information, not advice: it does not recommend a contribution, a rate, a product or a provider, and no figure on it is a personal recommendation.

Nothing you type here is transmitted or stored — there is no application server and no database. A share link is the exception: it carries your figures in the URL, and opening one is an ordinary request that carries them to the host. What that means.