Retirement Calculator
Estimate how much you could accumulate by retirement from your current savings and regular contributions, and how that compares with the income you expect to need. The result is a projection of your balance at retirement age based on the return rate you assume.
Retirement savings formula
The projection uses standard compound-growth arithmetic. With monthly contributions and monthly compounding:
FV = P × (1 + i)^n + PMT × ((1 + i)^n − 1) / i
Pis your current retirement savings.PMTis the monthly contribution.iis the assumed monthly return, the annual rate divided by 12.nis the number of months until retirement.
To translate a projected balance into income, a common rule of thumb is an initial withdrawal rate of around 4% of the balance per year, adjusted for inflation thereafter. It is a planning guideline drawn from historical studies, not a guarantee.
Worked example
Suppose you are 35, plan to retire at 65, contribute 500 per month, start from zero, and assume a 7% average annual return compounded monthly.
- Monthly rate:
i = 0.07 / 12 ≈ 0.005833, andn = 360 - Growth factor:
(1.005833)^360 ≈ 8.1165 - Future value:
500 × (7.1165 / 0.005833) ≈ 610,000
You would contribute 500 × 360 = 180,000 in total, so investment growth accounts for roughly 430,000 of the projected balance. At an example 4% initial withdrawal rate, 610,000 would support about 24,400 of income in the first year, before any pension or state benefits.
When to use this calculator
- Checking whether you are on track, by comparing the projected balance with the income you expect to need in retirement.
- Testing contribution changes, to see how raising your monthly savings today shifts the outcome decades later.
- Comparing retirement ages, since even a few extra working years add contributions and compounding while shortening the withdrawal period.
- Stress-testing assumptions, by running the projection at lower return rates to see a cautious scenario alongside an optimistic one.
Tips for interpreting the result
- Long-run returns are uncertain; run the projection with at least two return assumptions rather than relying on a single number.
- Use a return net of fees and, ideally, net of inflation so the result is in today's purchasing power.
- Employer contributions or matching, where available, raise the effective
PMTsignificantly and should be included. - Taxes on contributions, growth, and withdrawals vary by account type and country, and can materially change the income a balance supports.
- Revisit the projection yearly; small course corrections early are far cheaper than large ones near retirement.
Related calculators
The savings calculator covers shorter-horizon goals with the same compounding mechanics, and the income tax calculator helps estimate the after-tax value of retirement income. Before increasing contributions, the debt-to-income calculator and the debt snowball calculator help decide whether paying down debt should come first, while the business loan calculator is useful if business borrowing competes for the same cash flow.
These projections are estimates, not predictions; confirm your plan with current account terms and a qualified financial adviser before making major retirement decisions.