UK Retirement Calculator
Estimate the retirement pot you need, the sustainable income your savings could provide, any savings shortfall, and the monthly contribution that may close the gap.
Your retirement plan
Start with five figures. Open the optional sections to include pensions, fees and detailed assumptions.
Advanced options: pensions, fees and assumptions
Your results
Calculating…
Retirement pot neededTo fund the target over the selected period
Projected potToday’s money
Projected pot (nominal)Future pounds at retirement
Surplus or shortfall
Sustainable income– a year
Required monthly contributionYour contribution, excluding employer payments
Earliest viable retirement age
Return after feesNominal, before / in retirement
Ways to improve a shortfall
Plan comparison
Current plan
Stress-test scenarios
These are fixed assumptions, not success probabilities. They illustrate sensitivity and do not model sequence-of-returns risk.
| Scenario | Return before / after | Inflation | Pot at retirement | Earliest depletion age |
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The chart library did not load. All calculations and the yearly balance table below remain available.
Text alternative: yearly central-scenario balances
| Age | Stage | Balance |
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Methodology and calculation assumptions
The calculator uses one month-by-month model in real terms. “Nominal” means pounds at the date shown; “today’s money” removes assumed inflation so amounts have comparable buying power. This prevents retirement spending from becoming artificially cheaper over time.
Before retirement
The opening pot and one-off contribution grow for one month, then your and employer contributions are added at the end of each month. Contributions rise annually by the contribution-growth input and are deflated to today’s money.
monthly real return = ((1 + annual return) / (1 + annual fee) / (1 + inflation))^(1/12) − 1
balanceₘ = balanceₘ₋₁ × (1 + real returnₘ) + real contributionₘ
In retirement
At each month end, net spending from the invested pot equals your target less any active State Pension, defined-benefit pension, annuity or other recurring income. Entered incomes are treated as inflation-linked and before tax.
balanceₘ = balanceₘ₋₁ × (1 + real returnₘ) − max(0, target spending − recurring incomeₘ)
The required pot is found by a bounded search for the starting balance that reaches approximately £0 at the end of the chosen retirement period. If the real monthly rate is exactly zero, the month-by-month additions and withdrawals still work without division by zero.
Reverse calculations
Sustainable income is the highest level monthly spending that lasts through the selected period under the central assumptions. Required contribution is the level monthly personal payment that closes the projected pot gap, holding other inputs constant. Viable retirement age tests whole ages up to 80 while keeping the selected retirement duration unchanged.
Worked example
Generated from the same engine: calculating…
What the model excludes
Results are deterministic estimates, not financial advice or a promise. They exclude tax calculations, tax-free lump sums, benefit eligibility, investment volatility and sequence risk, changing asset allocations, contribution tax relief, salary limits, pension-access rules, care costs, irregular withdrawals, non-inflation-linked income and provider-specific charges. The model does not calculate a probability of success.
How to estimate retirement spending
Start with a current household budget, remove costs likely to end, and add housing, travel, care and irregular replacement costs that may continue. The 2025 Retirement Living Standards offer a useful conversation starter, not a personalised budget.
The standards’ moderate and comfortable budgets assume retirees are rent- and mortgage-free. If that will not apply, add expected housing costs to the preset. Run both a desired lifestyle and a lower essential-spending scenario.
Combining State and private pensions
Most people use more than one retirement-income source. Enter State Pension only from the age it begins; the calculator then reduces withdrawals from the invested pot. Add defined-benefit, annuity and other inflation-linked income separately. Use the official forecast because State Pension entitlement depends on your National Insurance record.
Interpreting a shortfall
A shortfall is the difference between the projected real pot and the real pot required for the selected cash flows. Treat the suggested contribution, retirement age and spending changes as planning levers, then rerun the calculation with cautious assumptions.
Returns, inflation, fees and risk
Use returns that match the intended asset mix and show fees separately. A small annual fee compounds over many years. Inflation affects both the buying power of the future pot and the real value of contributions that do not rise with prices.
Limits of the 4% rule
A fixed percentage is a rough reference rather than a UK guarantee. Retirement length, fees, taxes, inflation, asset allocation and flexible spending all matter. This calculator’s cash-flow pot is tailored to the selected duration and income dates, but is still only a fixed-return projection.
Sequence risk and longevity
The order of real-world returns matters once withdrawals begin: poor early returns can cause more damage than the same poor returns later. The three scenarios vary assumptions but do not reproduce market sequences. Consider a longer retirement period, lower returns and higher inflation, and seek regulated advice for decisions with lasting consequences.
Tax note: results are before tax. State Pension and most pension income may be taxable; account and withdrawal treatment varies.
UK retirement calculator FAQs
How much money do I need to retire in the UK?
It depends on your spending goal, retirement length, other pension income and investment assumptions. This calculator estimates the pot needed by modelling the monthly amount your investments must provide after State Pension and other recurring income.
How much should I save each month for retirement?
Enter your current pot, retirement age and desired income. The required monthly contribution result estimates the level monthly amount needed from now to retirement, in addition to employer contributions and any one-off contribution.
Does the calculator include the UK State Pension?
Yes, optionally. Enter your own forecast amount in today’s money and the age it starts. The calculator does not assume everyone receives the full State Pension because entitlement varies.
How are inflation and pension fees handled?
The engine converts returns, fees and inflation to effective monthly rates and calculates in today’s money. Fees reduce investment growth, while income and spending entered in today’s pounds retain their real buying power.
Are the retirement income results before or after tax?
They are before tax. Pension and State Pension income can be taxable, while treatment varies by account and withdrawal type. Add a margin or use a net spending target that reflects your circumstances.
How long might my pension pot last?
The scenario table shows an estimated depletion age over your selected retirement period. It is a fixed-assumption projection, not a guarantee, and does not model the order of actual market returns.
Is the 4% rule suitable for a UK retirement?
The 4% rule is only a rough reference, not a promise or personalised recommendation. Its outcome depends on retirement length, fees, asset mix, market sequence, inflation, taxes and whether spending changes.
How does early retirement change the result?
Retiring earlier usually means fewer contribution months, more withdrawal months and possibly a gap before State Pension starts. Test an earlier age directly and compare the required pot, contribution and depletion age.
Sources, authorship and review
- Pensions UK, Retirement Living Standards in the UK: 2025 update — lifestyle budgets and housing assumptions.
- GOV.UK, Check your State Pension forecast — personalised amount and starting age.
- GOV.UK, The new State Pension: what you’ll get — entitlement varies with National Insurance record.
- MoneyHelper pension calculator guidance — combining State, defined-benefit and defined-contribution income.
- GOV.UK, Tax when you get a pension — pension income and tax.
Built by: Starlight Robotics calculator teamPublished: 22 November 2025Last reviewed: 17 July 2026Professional review: none claimedCalculation methodology
Change log
- : rebuilt the engine in real terms; corrected depletion timing; added UK income sources, fees, lifestyle targets, reverse calculations, scenarios, accessible tables and documented tests.
- : initial calculator published.
Privacy: input values are processed locally in your browser. Educational disclaimer: this tool provides illustrative estimates only and is not financial, tax or investment advice.