Investment and retirement calculator

This calculator projects how large your retirement savings could grow by the time you retire, based on what you have already saved, how much you add each month, and the return you expect. It also estimates the yearly income that pot might provide using the widely cited 4% rule. It works for pensions, 401(k)s, ISAs, and general investment accounts.

How the projection works

Starting from your current savings, the tool adds your monthly contribution and applies compound growth every month until your chosen retirement age. It then splits the final pot into the amount you contributed and the growth earned. The "4% rule" estimate assumes you could withdraw about 4% of the pot in your first year of retirement as a sustainable income.

Getting a realistic estimate

Long-term stock market returns have historically averaged around 5–8% per year before inflation, but returns vary and are never guaranteed. Try a lower rate for a cautious view. Remember this projection is in today's contributions; you may be able to increase them over time. To plan monthly saving, use our budget calculator.

Using it as a UK pension calculator

For a UK workplace or personal pension, enter your current pension pot as the starting savings and your combined monthly contribution, including your employer's share and tax relief, since all of it goes into the pot. The default retirement age of 67 matches the planned UK State Pension age; your State Pension (currently around 11,970 pounds a year at the full rate) would come on top of the private pot projected here. Auto-enrolment minimums (8 percent of qualifying earnings) are a floor, not a target — projecting a few contribution levels shows quickly how much difference an extra 50 or 100 pounds a month makes.

Using it as a 401(k) or IRA calculator

US savers can use the same projection for a 401(k) or IRA: enter your current balance, then a monthly contribution that includes any employer match — matching dollars compound just like your own. Social Security is paid separately, so treat the projected pot as the investment side of your retirement income. Run the calculator with a lower return (4 to 5 percent) to see a cautious scenario alongside an optimistic one.

Frequently asked questions

What is the 4% rule?

It is a guideline suggesting you can withdraw about 4% of your retirement pot in the first year, then adjust for inflation, with a good chance the money lasts 30 years. It is a rule of thumb, not a guarantee.

What growth rate should I use for retirement planning?

A common range is 5 to 7 percent per year for a diversified stock-heavy portfolio before inflation, or about 3 to 5 percent in real (after-inflation) terms. Using a real return keeps the result in today's money, which is easier to interpret. Pension providers in the UK often illustrate at around 2, 5, and 8 percent; running all three here gives you the same low, mid, and high view.

How much do I need to retire?

A rough rule is 25 times the annual income you want from your investments (the inverse of the 4 percent rule). So for 20,000 pounds or dollars a year on top of state benefits, you would target a pot of around 500,000. Your own number depends on retirement age, other income, and lifestyle.

Disclaimer: This calculator provides estimates for informational purposes only and is not financial or investment advice. Investment values can fall as well as rise. Consider speaking to a regulated financial adviser.