Retirement Calculator
Project retirement balance from current savings, monthly contributions, and expected return.
Written by Golam Rabbani, Founder & Lead Engineer — Last updated 2026-05-01
How to use this retirement calculator
- Enter your current age and target retirement age.
- Enter the balance you already have saved for retirement (optional).
- Enter the amount you plan to contribute each month.
- Enter the annual return you expect on the portfolio (as a percentage).
- Pick your currency.
- Press Calculate to see the projected balance at retirement, total contributions, and growth.
- Use Copy to save the projection or Reset to clear all fields.
About this retirement calculator
The retirement calculator projects what your savings could grow to by the time you retire, using monthly compounding for both your starting balance and your ongoing contributions.
The formula is the future value of a lump sum plus the future value of an ordinary annuity: FV = P × (1 + i)^n + PMT × ((1 + i)^n − 1) / i, where P is current savings, PMT is monthly contribution, i = annual_return / 12, and n = years × 12. Total contributed is P + PMT × n; growth is FV − total contributed.
Worked example: age 30 retiring at 65, current savings 20,000, monthly contribution 500, expected return 7%. Years = 35, n = 420, i = 0.07/12 ≈ 0.005833. (1+i)^n ≈ 11.435. Lump grows to 20,000 × 11.435 ≈ 228,700. Annuity = 500 × (11.435 − 1)/0.005833 ≈ 894,490. Balance at 65 ≈ 1,123,190. Total contributed 230,000; growth ≈ 893,190.
This is a projection, not a promise. It uses one constant return rate; real markets are volatile and inflation, taxes, and fees can materially reduce the real-world figure. Returns are not guaranteed. Not financial advice — consult a qualified planner for your specific situation.
FAQ
- What return rate should I assume?
- A long-run global stock index has historically averaged around 6–8% per year nominal, and a balanced portfolio less. Use a conservative number you can defend; you can rerun the tool with a few rates to see how sensitive the answer is.
- Does this calculator account for inflation?
- No. The result is in today's currency units at nominal returns. If you want a real (inflation-adjusted) figure, subtract your expected inflation rate from the annual return before entering it — for example use 4% instead of 7% if you expect 3% inflation.
- How are taxes handled?
- They are not modelled here. If your account is a traditional 401(k) or IRA, the balance is pre-tax — you will pay income tax on withdrawals. For a Roth account the projection is already after-tax. Plan accordingly.
- What happens if I leave current savings or monthly contribution blank?
- They are treated as zero. Leaving both blank with a non-zero return rate gives a future value of zero, which is the math working as intended.
- Why monthly compounding instead of yearly?
- Most retirement accounts contribute monthly and reinvest dividends throughout the year, so monthly compounding tracks the typical experience more closely than annual compounding without being more sensitive to assumptions.
- Is anything stored or sent to a server?
- No. All calculation runs in your browser; nothing is sent or saved. Closing the page clears every input.