Retirement Calculator
Project your retirement savings from your contributions and expected return.
Results update as you type.
About this calculator
A retirement calculator projects how much your savings could grow by the time you retire, from your current age, retirement age, current balance, monthly contribution and an expected annual return. Each month it adds your contribution and applies one-twelfth of the return to the running balance, compounding year after year until your retirement age, then splits the final pot into what you paid in versus what investment growth added.
For example, starting at age 30 with 20,000 saved and adding 500 a month at a 6% annual return, the balance grows to roughly 875,000 by age 65. Of that, only about 230,000 is money you actually contributed — the remaining 640,000 or so is compound growth. Set an inflation rate under advanced options to also see the pot in today’s money.
Use it to check whether your saving rate is on track, to see how retiring a few years later or nudging up the monthly contribution changes the outcome, and to grasp how much of a nest egg comes from decades of compounding rather than from deposits alone.
Frequently asked questions
What return rate should I assume?
Long-run stock-market returns have historically averaged around 6–7% after inflation, but returns are not guaranteed and vary year to year. Use a conservative figure for planning.
Does this account for inflation?
No — it projects nominal balances. To think in today’s money, use a real return (your expected return minus expected inflation) as the rate.
How much do I need to save each month for retirement?
That depends on your target pot, your age and your expected return. Enter a monthly contribution and adjust it until the balance at retirement reaches the figure you want — the calculator shows the result update as you change the amount.
Does starting to save earlier really make that much difference?
Yes, because contributions made in your twenties compound for an extra decade or two. Try moving the current age earlier while keeping everything else fixed and watch how much larger the balance at retirement becomes.
What is the "in today’s money" figure?
It discounts the projected balance back by your assumed inflation rate, so a future 875,000 might be worth far less in purchasing power. It answers what the pot would buy in today’s prices rather than the raw future number.
Can I increase my contribution each year?
Yes. Set an annual contribution increase under advanced options, and the calculator raises your monthly contribution by that percentage every year — useful for matching expected pay rises.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/retirement/curl
curl "https://calculator.free/api/v1/retirement/?current_age=30&retire_age=65¤t_savings=20000&contribution=500&return_rate=6"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/retirement/?" + new URLSearchParams({
"current_age": "30",
"retire_age": "65",
"current_savings": "20000",
"contribution": "500",
"return_rate": "6"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.