Finance
Retirement Calculator
Your nest egg grows by FV = PV·(1+r)^n + PMT·((1+r)^n − 1) ÷ r. Enter your age, savings and monthly contribution to project the balance at retirement, see how much is growth versus your own deposits, and how much starting earlier is worth.
Your plan
How old you are now
yrs
When you plan to stop working
yrs
What is already in your retirement accounts
$
What you add each month, including any employer match
$
Long-run average — a diversified portfolio is often modelled at 6–8%
%
Optional — raise your contribution each year with your pay
%
At age 65
$1,188,181
35 years of saving · 7.0% return
Contributions $235,000Growth $953,181
Total you put in
$235,000
Investment growth
$953,181
Started with
$25,000
You contributed
$210,000
Growth does the heavy lifting
More than half of your $1,188,181 comes from returns, not from your own deposits — the payoff of a long runway.
Estimate only. Real returns vary year to year and are not guaranteed; this projection assumes a steady average and ignores taxes, fees and inflation.
Try a scenario
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The basics
What drives a retirement balance?
Three things build a nest egg: what you start with, what you add, and how long it compounds. Two ideas carry most of the weight.
growth on growth
Compounding is the engine
Returns earn returns of their own. Over decades the money the market adds dwarfs the money you deposit — which is why the balance curves upward instead of rising in a straight line.
$500/mo for 35 years at 7% → $1,188,181, mostly growth
time beats amount
Starting early is the cheat code
A dollar saved at 25 has forty years to compound; the same dollar at 45 has twenty. The early start wins by more than the extra deposits alone — time is the ingredient you cannot buy back.
Age 25 → $1,393,964; age 45 → $280,657, same deposit
Method
How the projection is built
Four steps take you from your age today to a balance at retirement.
- 1
Count the years and the months
Subtract your age from your retirement age for the years you have, then multiply by twelve for the number of monthly periods n.
(65 − 30) × 12 = 420 months - 2
Turn the annual return into a monthly rate
Divide the expected annual return by twelve for the periodic rate r. Returns are not guaranteed, so use a sober long-run average.
7% ÷ 12 = 0.5833% a month - 3
Grow the balance and the contributions
The starting balance compounds, and each monthly contribution compounds from the day it lands. The future-value formula does both at once.
FV = PV·(1+r)^n + PMT·((1+r)^n − 1) ÷ r = $1,188,181 - 4
Split the result into deposits and growth
Subtract everything you put in from the final balance to see how much the returns added — usually the larger share over a long runway.
$1,188,181 − $235,000 = $953,181 growth
Worked examples
The cost of waiting to start
$500 a month at 7%, starting with $5,000, to age 65. The only thing that changes is the start age — and it changes everything.
| Start age | Years | You put in | Balance at 65 |
|---|---|---|---|
| 25 | 40 | $245,000 | $1,393,964 |
| 30 | 35 | $215,000 | $958,058 |
| 35 | 30 | $185,000 | $650,568 |
| 40 | 25 | $155,000 | $433,663 |
| 45 | 20 | $125,000 | $280,657 |
Where it shows up
The decisions it informs
Three questions this projection helps you answer.
am I on track?
Checking your pace
Project your balance and set it against a target — 25 times your expected annual spending. The gap tells you whether to save more, work longer, or adjust the plan.
Compare the projection to a 25× target
save more or wait?
Weighing a change
Retirement math has two levers: how much you save and how long you save it. The tool lets you price each against the other before you commit.
Test +$200/mo vs retiring two years later
capture the match
Prioritising accounts
Seeing how much the match adds over decades makes the case for capturing every dollar of it before putting money anywhere else.
An employer match is an instant return
Reference
Return assumptions and account types
General guidance, not advice. The return you assume is the single biggest lever on the result — so test more than one.
test more than one
Return bands people model
A rough planning range: 5% conservative, 7% middle, 9% optimistic — before inflation. Subtract 2–3% to see the figure in today's dollars.
tax treatment differs
Where the money sits
A traditional 401(k)/IRA is taxed on withdrawal; a Roth is funded with after-tax money and grows tax-free. Employer matches land in a traditional account.
Worth knowing
Five things that move the number
Small levers, large effects over decades.
raise it yearly
Increase with your pay
Bumping your contribution a little each year, in step with raises, lifts the ending balance far more than the small annual increase suggests. The tool has a field for it.
fees compound too
Costs eat returns
A 1% annual fee does not sound like much, but over 35 years it can quietly remove a large slice of the balance. Low-cost index funds keep more of the return.
free money first
Never skip the match
An employer match is an immediate, guaranteed return on your contribution. Capture the full match before saving in any other account.
inflation is silent
Think in real terms
The projection is a nominal figure. What it buys depends on inflation — a reason to plan with a return net of 2–3%, not the headline number.
don't panic-sell
Time in the market
The long-run averages only apply if you stay invested through the down years. Selling in a downturn locks in the loss and forfeits the rebound.
catch-up exists
Over 50 can add more
The IRS allows extra catch-up contributions once you turn 50 — a way for late starters to close the gap faster.
Quick chart
What a monthly contribution grows to
Balance from a monthly contribution at 7%, starting from zero — read the row for your deposit and the column for your runway.
| Per month | 10 yrs | 20 yrs | 30 yrs | 40 yrs |
|---|---|---|---|---|
| $200 | $34,617 | $104,185 | $243,994 | $524,963 |
| $400 | $69,234 | $208,371 | $487,988 | $1,049,925 |
| $600 | $103,851 | $312,556 | $731,983 | $1,574,888 |
| $800 | $138,468 | $416,741 | $975,977 | $2,099,851 |
| $1,000 | $173,085 | $520,927 | $1,219,971 | $2,624,813 |
| $1,500 | $259,627 | $781,390 | $1,829,956 | $3,937,220 |
Assumes a steady 7% annual return, contributions at month end, no starting balance.
How we calculate this
The formula and our assumptions
The projection is future value with monthly contributions, simulated month by month.
FV = PV·(1+r)^n + PMT·((1+r)^n − 1) ÷ r
Future value
PV is your starting balance, PMT the monthly contribution, r the annual return over twelve, and n the number of months. A yearly step-up raises PMT each year.
growth = FV − everything you put in
Contributions vs growth
Every dollar you deposit is principal; the rest of the ending balance is growth. Over a long runway growth is usually the larger share — the point the chart makes.
- The return is treated as a steady monthly average; real markets are volatile year to year.
- Contributions are added at the end of each month and compound from the next month.
- The result is nominal — before inflation, taxes and investment fees.
- Include any employer match inside your monthly contribution.
Sources
Where the method comes from
- Internal Revenue Service — 401(k) and IRA contribution and catch-up limits.
- U.S. Securities and Exchange Commission (Investor.gov) — compound interest and saving for retirement.
- Standard future-value-of-an-annuity formula for regular contributions.
FAQ
Common questions
Your balance compounds each month: FV = PV·(1+r)^n + PMT·((1+r)^n − 1) ÷ r, where PV is what you have now, PMT the monthly contribution, r the annual return over twelve, and n the months. Starting at $25,000 and adding $500 a month for 35 years at 7% grows to about $1,188,181 — of which $953,181 is growth and only $235,000 is money you put in.
Work backwards from a target. A common rule of thumb is to aim for 25 times your expected annual spending — so $60,000 a year in retirement points to a $1.5 million nest egg. Enter that as your goal, and the calculator (via the required-contribution math) shows the monthly amount that reaches it by your retirement age. Starting earlier lowers the monthly figure dramatically.
Because growth compounds on growth. Saving $500 a month from age 25 reaches about $1,393,964 by 65, but waiting until 45 leaves only about $280,657 — the same monthly deposit, less than half the result. The extra 20 years do far more than the extra deposits, because early dollars have the longest time to compound.
No return is guaranteed, so use a long-run average and be honest. A diversified stock-and-bond portfolio is often modelled at 6% to 8% a year before inflation. Conservative planning uses 5%; 7% is a common middle. A higher assumption makes the projection look better but does not make the market pay it — test a lower rate to see your plan's floor.
Include the match in your monthly contribution. If you put in $500 and your employer adds a 50% match up to a limit, enter the combined amount that actually lands in the account each month. An employer match is free money and an immediate return on your contribution — capture the full match before saving anywhere else.
The IRS sets the limits each year. In recent years a 401(k) allowed roughly $23,000 in employee contributions, with an extra catch-up amount once you turn 50, and an IRA allowed around $7,000. Employer matches are on top of the 401(k) employee limit. Because the figures rise most years, check the current IRS limits before maxing out.
No — it projects the nominal balance. In real terms, $1 million in 35 years buys less than $1 million today, so many planners subtract 2–3% from the return to see the figure in today's dollars. Taxes depend on the account: a traditional 401(k) is taxed on withdrawal, a Roth is not. Treat the result as a before-tax, before-inflation estimate.
A guideline for spending in retirement: withdrawing about 4% of your nest egg in the first year, then adjusting for inflation, has historically lasted roughly 30 years. It is the mirror of the 25× savings target — 4% is one twenty-fifth. On a $1,188,181 balance that is about $47,527 of income in year one.
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Ugo CharlesBuilt and fact-checked against our editorial standards · Last updated June 2026
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