Retirement calculator: when you can afford to retire, and how much you can spend

Most retirement calculators multiply your spending by 25 and hand you a single number. That answers a different question from the one most people are actually asking. A number tells you what a portfolio might sustain forever; it does not tell you whether your money holds, year by year, through the specific life you intend to live. This retirement calculator projects the whole thing instead: cash, assets and net worth for every year from now to the end of life.

Four questions, one model

Planning Mode sits at the top of the input panel and decides which question the calculator answers. All four run the same year-by-year engine on the same figures, so switching between them costs you nothing and changes only what is being worked out.

Retire as early as possible. The earliest age you could afford to stop working: the lowest age at which the plan still holds in every year, tested against the cash reserve and the legacy you set. This is the early retirement calculator most people arrive looking for.
Retire at a chosen age. Pick any age between today and your state pension age. The projection starts from today, assumes your main employment stops at that age, and reports whether the money lasts your whole plan, plotted against carrying on to state pension age so you can see what the earlier date costs.
Make the most of retirement. Already stopped? Enter what you own and what you receive, and the calculator works out the most you could spend on living costs each year while still holding your cash reserve and still leaving behind the amount you set.
Plan my finances over time. No retirement date in mind yet? This one assumes you stop at your state pension age, so there is nothing to choose, and reports what you are worth by the time you get there. It is the mode for weighing a decision rather than a date: change the house, the child or the career move, and watch that figure move with it.

What it calculates

The model runs your figures forward one year at a time, then reports the earliest age the plan survives, how far the money reaches at an age you have chosen, the annual spending that plan can support, or the net worth it reaches by retirement, depending on the mode. Where a plan gives out, it names the age the money reaches rather than quietly returning an optimistic figure. The model is deterministic by design: the same inputs produce the same projection, with no randomness and no simulation to re-roll.

What it models that a rule of thumb cannot

Pensions on their own timetable. Retire before yours begins and you fund the gap from savings; stopping earlier also shrinks the pension itself, through fewer contribution and growth years. Already drawing one? Enter it with its real start age and it pays from the first projected year.
Property as part of the plan. Homes, rental income, planned sales, future purchases and downsizing, each landing in the year you schedule it.
A partner on a different timetable. Two people, two retirement ages, two pensions, one household cash flow.
Market crashes and their recovery years, so you can see what a bad first year of retirement does to the rest of the plan.
One-off events: a lump sum, a wedding, a loan repaid, support for a child ending.
Spending that changes with age, rather than one flat figure held constant for forty years.

What it does not do

It does not model tax in any jurisdiction, and it does not attempt sequence-of-returns risk statistically the way a Monte Carlo tool does. A chosen retirement age cannot be set beyond your state pension age: work past that point belongs in the part-time and other-income fields, with its own end age, rather than in the retirement date. It applies the growth and inflation assumptions you give it, which means the output is only as good as those assumptions. It is an educational planning tool, not financial advice, and it makes no personal recommendation. Read the full methodology, including every default assumption and an honest list of what the model does not do.

Your figures stay on your device

There is no account, no signup and no email. The calculation runs entirely in your browser, and the numbers you type are never transmitted anywhere. Saved scenarios are stored in your own browser's local storage and you can clear them at any time.

Common questions

How is this different from a 4% rule calculator?

The 4% rule tests whether a portfolio survives a fixed retirement length at a fixed withdrawal rate. It was not designed to find the earliest age a particular household can stop, and it has no way to price a pension that starts in twelve years, a house sold in year eight, or a partner who keeps working.

What does "earliest viable retirement age" mean?

The earliest age your plan supports while keeping your cash reserve every year and leaving at least the amount you set at the end. It is tested year by year, not checked once.

Can I plan for a specific retirement age, like 60?

Yes. Set Planning Mode to "Retire at a chosen age" and enter it. The projection assumes work stops at that age and reports whether the plan lasts, so you can try 55, 60 and 62 in turn and see what each one costs. Any age from today up to your state pension age works.

How much can I spend in retirement without running out?

Choose "Make the most of retirement" to find your highest annual living budget while keeping your cash reserve throughout the plan and leaving at least the amount you want at the end. Mortgage payments, support for dependants and other costs remain as entered. The result uses your goals, not a fixed withdrawal rate.

What if I am not planning a retirement date yet?

Choose "Plan my finances over time" to model retirement at your state pension age, so there is no date to choose, and see your projected net worth by then. Test decisions such as moving home, having a child or changing careers. The figure is future money, not today's: for someone in their thirties, several decades of inflation sit inside it. If you are already at or past state pension age, choose "Make the most of retirement" instead.

How long will my money last in retirement?

When a plan does not hold, the calculator names the age the money reaches rather than only reporting that it failed. Change a figure and that age moves with it, so you can see which lever buys the most years.

Do I need exact figures to start?

No. Rough figures give a usable first answer, and the projection sharpens as you replace estimates with real numbers. Start with the thirty-second estimate if you would rather not fill in everything at once.

Can I compare two retirement ages?

Yes, and what it compares follows the mode. Looking for the earliest age, the charts plot it against any comparison age you choose. Planning around a chosen age, they plot that age against carrying on to state pension age. Either way you see both lines at once, and what the extra years buy you. The other two modes plot a single line, because only one retirement age is in play.

How the model works · How to use this calculator, section by section · How much do you need to retire early? · How much can you spend in retirement? · Retiring at 55 · Retiring at 60 · All guides