Retirement Calculator
Retirement Calculator PRO
Project retirement savings, spending, pensions, income gaps, required contributions and Monte Carlo success probability.
Regional profiles set currency, locale and official-service links. They do not calculate legal pension entitlement.
Retirement ages, contribution rules and public pension formulas can change. Replace example values with your official personal forecast.
Timeline
Savings and contributions
Returns, inflation and costs
Exact real return = (1 + nominal return after costs) ÷ (1 + inflation) − 1.
Investment returns are uncertain and can be negative, especially over short periods.
Small annual fees can materially reduce long-term balances.
The tax-drag field is a simplified annual portfolio cost and does not model country tax law.
Retirement spending
Inputs marked as today’s money are increased by the selected inflation or indexation assumptions.
Income above spending is added to the portfolio only when the surplus option is enabled.
Pension and other retirement income
Enter state and occupational pension amounts from official or provider forecasts.
Use the official pension service for legal entitlement and a personal public-pension forecast.
Risk and stress assumptions
Monte Carlo results are simulations, not probabilities guaranteed by real markets.
A planning withdrawal rate is a scenario input, not a safe or guaranteed rate.
Using the same seed makes Monte Carlo results reproducible.
Results depend on the assumptions entered and should be compared across several scenarios.
Inflation changes both future spending and the real value of savings.
Planning to a longer age increases the required retirement resources.
The calculator does not convert currencies. Keep all amounts in one currency.
This tool provides planning estimates and is not financial, tax or legal advice.
All calculations run locally in the browser.
Results
A retirement calculator turns a set of assumptions into a long-term cash-flow model. It can project savings before retirement, compare a desired retirement budget with pension income, estimate a required monthly contribution, test an earlier retirement age and show how inflation, fees and uncertain investment returns may affect the plan.
The result is a planning estimate, not a legal pension forecast or a promise of future investment performance. State-pension entitlement depends on national rules, birth year, contribution record and other personal data. Use the regional profile to open the relevant official service, then enter the personal forecast rather than relying on a generic example.
What the calculator models
The calculator separates retirement planning into two phases. During accumulation, the portfolio receives investment returns and contributions. During retirement, it receives any continuing return, pays the chosen spending target and adds active pension or employment income.
Seven modes are available:
- a full retirement plan;
- the monthly contribution required to meet the plan;
- the maximum sustainable retirement spending;
- the earliest retirement age supported by the assumptions;
- capital needed to bridge an early-retirement period;
- the gap between retirement spending and expected income;
- a seeded Monte Carlo stress test.
Set a realistic timeline
The timeline uses current age, retirement age, planning age and an age for later-life spending changes. The planning age is a safety horizon rather than a prediction of death. Longer horizons usually require more capital, while statutory retirement ages and longevity assumptions differ across countries.
Enter current savings and future contributions
The accumulation model starts with current retirement savings. It then adds:
- the employee’s monthly contribution;
- an employer contribution calculated as a percentage of gross salary;
- an annual extra contribution;
- annual growth in contributions.
The employer contribution is calculated as:
Employer monthly contribution = annual gross salary ÷ 12 × employer contribution rate.
Contribution growth can represent regular pay growth or a plan to increase savings. It should not be entered as a guarantee. A promotion, job change, career break or contribution cap may change the actual amount.
Understand compound growth
Before retirement, the calculator works month by month. Each period applies the net return to the existing balance and then adds contributions. Compound growth means returns can earn further returns over time.
Investor.gov illustrates the same principle: initial capital, regular additions, time and return jointly determine future value. Small assumption changes can become substantial over decades.
Account for fees and tax drag
The calculator reduces the gross return using annual fees and a simplified tax-drag field:
Net annual return = (1 + gross return) × (1 − annual fee) × (1 − tax drag) − 1.
This is a modelling shortcut, not a country tax calculation. Real taxes may depend on account type, realised gains, withdrawals, allowances and residency. Enter zero when tax is already reflected elsewhere or when the account is tax-deferred and the model is intended to remain pre-tax.
Ongoing fees deserve attention because they reduce the capital that remains invested. The U.S. Securities and Exchange Commission’s Investor.gov explains that both transaction and ongoing fees reduce portfolio value, and even small annual differences compound over long periods.
Convert nominal returns into real returns
Retirement spending depends on purchasing power, not only the nominal account balance. The exact real-return formula is:
Real return = (1 + net nominal return) ÷ (1 + inflation) − 1.
Subtracting inflation from return is a rough approximation. The difference becomes more important when the rates are high.
Choose a retirement-spending target
The calculator supports two methods: a fixed annual budget in today’s money or a replacement ratio based on current gross salary.
A salary percentage is convenient, but it may not match the user’s actual needs. Mortgage payments may end, commuting costs may fall and health, care or leisure spending may rise. A detailed household budget usually provides a stronger target than a single replacement percentage.
The late-life spending factor can reduce or increase spending after a chosen age. A one-time retirement cost can represent a major purchase, debt repayment or relocation. A desired legacy is entered in today’s money and carried forward with inflation.
Add pension and other retirement income
Each income source has an amount in today’s money, a start age, an end age and an annual indexation assumption. Supported sources include public pension, occupational pension, private pension, annuity income, part-time work and other income.
The amount active in a given year reduces the portfolio withdrawal:
Portfolio withdrawal = max(0, retirement spending − active pension and other income).
When income exceeds spending, the surplus is added to the portfolio only when the surplus option is enabled. This avoids silently assuming that every unused payment is reinvested.
Why official forecasts matter
Public-pension systems do not use one universal formula. Official services in the UK, France, Germany and Sweden use national records and current rules to produce personalised forecasts. Enter those results alongside private savings instead of asking a general calculator to replace them.
Full retirement-plan result
The full mode shows projected and required capital, funding ratio, shortfall and the monthly drawdown path. A ratio above 100% means only that the deterministic assumptions fund the selected spending and legacy target.
Required monthly contribution
Because pension starts, inflation, fees and legacy goals interact, the calculator tests monthly employee contributions with a binary-search solver. Compare the result with current and employer contributions, then review retirement age, spending, fees and pension assumptions together.
Sustainable retirement spending
This mode finds the highest annual spending amount in today’s money that keeps the deterministic plan funded. “Sustainable” applies only to the entered assumptions; lower returns, higher inflation or a longer retirement can reduce it.
Earliest feasible retirement age
The earliest-age mode tests each integer age from the next year onward. Retiring earlier leaves less time to save and adds withdrawal years. The first funded age is financial, not statutory.
Early-retirement pension bridge
The bridge mode estimates capital needed between an early retirement date and the first positive pension-type income. It values expected spending less active income and includes the one-time retirement cost.
Retirement income gap
The income-gap mode compares the target budget with guaranteed income at retirement. It also estimates portfolio income using the user’s planning withdrawal rate.
Guaranteed income gap = target spending − guaranteed retirement income.
Combined gap = target spending − guaranteed income − portfolio income.
The withdrawal rate remains an assumption. It is not labelled “safe” because sustainable rates depend on retirement length, asset mix, fees, inflation and the sequence of returns.
Monte Carlo stress testing
Monte Carlo mode generates many annual return paths from the entered expected returns and volatility. A trial succeeds when the portfolio lasts to the planning age, and the report shows success frequency plus 10th, 50th and 90th percentile ending balances. The percentage remains model-dependent rather than guaranteed.
Sequence-of-returns risk
Two retirees can earn the same long-run average return yet experience different outcomes when withdrawals occur in a different order. Losses near retirement can be especially damaging because withdrawals leave less capital available for a later recovery.
Research by Wade Pfau and other retirement scholars shows that vulnerability is greatest around the retirement date. The calculator therefore includes a poor-first-years stress scenario in addition to Monte Carlo simulation.
How to build a more credible scenario
- Use current balances from actual pension and investment statements.
- Enter public and occupational pensions from official forecasts.
- Build a retirement budget in today’s money.
- Include realistic investment fees.
- Use more than one return and inflation scenario.
- Choose a planning age that leaves a longevity margin.
- Add temporary income only for the years it is expected.
- Separate one-time retirement costs from annual spending.
- Review the plan after salary, employment or pension-rule changes.
- Keep all figures in one currency and on the same pre-tax or post-tax basis.
Common mistakes
- using a generic public-pension amount instead of a personal forecast;
- treating expected return as guaranteed;
- ignoring inflation in retirement spending;
- ignoring investment fees;
- mixing gross income with net spending;
- assuming every income source begins at retirement;
- using a fixed withdrawal rate as a promise;
- planning only to average life expectancy;
- reading Monte Carlo success as certainty;
- failing to update the plan when circumstances change.
Frequently asked questions
Does the calculator determine my legal retirement age?
No. It tests a financial retirement age. Use the official pension service for statutory eligibility and public-pension dates.
Should I enter pension income before or after tax?
Use one consistent basis. If spending is after tax, income should ideally be entered after estimated tax as well.
Is the Monte Carlo percentage guaranteed?
No. It reflects the chosen return, volatility, inflation and modelling assumptions.
Why does the calculator use today’s money?
Today’s money makes future spending easier to understand. The model then applies inflation internally.
What is a pension bridge?
It is capital used to cover spending between an early retirement date and the later start of public or occupational pension income.
Is the planning withdrawal rate a safe withdrawal rate?
No. It is a scenario input used to estimate portfolio income and should be stress-tested.
Official and primary sources
- GOV.UK: Check your State Pension forecast
- GOV.UK: Plan your retirement income
- L’Assurance retraite: estimate your pension
- Deutsche Rentenversicherung: retirement start and amount calculator
- Pensionsmyndigheten: pension forecast
- OECD: Pensions at a Glance 2025
- Investor.gov: Compound Interest Calculator
- Investor.gov: Understanding fees
- Wade Pfau: The Lifetime Sequence of Returns
- Collins, Lam and Stampfli: How Risky Is Your Retirement Income Risk Model?
Sources reviewed: 23 June 2026.
