Retirement calculator
Project your savings and what they could pay each year.
About this calculator
Enter your age, savings and monthly contributions to see a projected balance at retirement. Works for a US 401(k) or IRA and for a UK workplace pension, SIPP or ISA, since it uses only the amounts you enter.
It does not include tax, employer matching rules or government pensions, so add any employer contribution to your monthly saving. The income figure uses the 4% rule of thumb, which is a planning guide and not a guarantee.
How it works
Projects your balance with monthly deposits, deflates it by inflation, and applies a 4% first-year withdrawal.
Worked example
- Your age: 30 years
- Retirement age: 65 years
- Saved so far: $40,000
- Monthly saving: $500
- Annual return: 5%
- Inflation: 2% a year
At age 65: $797,395 (about $398,719 in today's money)
The story behind it
Where the idea came from: William Bengen, financial planner, 1994 (the 4% rule).
The 4% figure used here comes from William Bengen. In a 1994 paper, he tested withdrawal rates against decades of historical market returns and found that about 4% in the first year had lasted at least 30 years in every period he looked at. It's a planning guide, not a promise, which is why this calculator also shows your balance in today's money.
Why you can trust this calculator
- It runs in your browser. Nothing you type into it is sent anywhere.
- The method is explained on this page, so you can check it yourself.
- Free to use, with no sign-up.
- Results are estimates, not financial advice.
- Spotted a mistake? Tell us and we'll look into it.
After 15 years as a mathematics educator, I built CalculStore to give students, teachers, professionals and anyone working with numbers simple, reliable tools.
Meet the founder