Tool 05 · Retirement number
How big a pot do you need?
Start from the life you want, not a guess. Pick your yearly spending and target age, and this works backwards to the number you need — and the monthly saving that gets you there.
Save $0/month to reach it by 60.
Number = yearly spending ÷ withdrawal rate.
Pro features. Model raises and fees, read insights, compare target ages, and export the plan.
Sharpen the plan
Refine the model
Starting lower and stepping up as you earn more lowers the monthly you need now.
Fees lower your net return, so you must save more to hit the number.
Year by year
Compare target ages
| Retire at | Save per month | You'll contribute |
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How to find your retirement number
Your retirement number is the size of pot that lets your investments cover your spending for life. It’s calculated from the lifestyle you want, not a generic target: take your desired yearly spending in retirement and divide by your withdrawal rate (4% gives the classic 25× figure).
The calculator then works out the monthly saving needed to reach that number by your target age, given what you’ve already saved and your expected return. The stacked chart breaks the final pot into three parts — what you’ve already saved, your future contributions, and the growth on top. Pro lets you model annual pay raises and investment fees, both of which change the monthly figure.
The reason to work backwards from spending — rather than aiming at a round number like "a million" — is that your number is deeply personal. Two people the same age can need wildly different pots simply because one is happy on €25,000 a year and the other wants €60,000. Anchor the target to the life you actually want, and the monthly saving to fund it becomes a concrete, motivating figure instead of a vague worry.
A worked example
€40,000 spending · 4% withdrawal · age 30 → 60 · €30,000 already saved · 7% return
The number needed is €40,000 ÷ 4% = €1,000,000. Starting with €30,000 and 30 years to go, you’d need to save about €620 a month to get there. Delay to 40 and the required monthly saving roughly triples — a stark reminder that the cheapest time to start was yesterday, and the second-cheapest is today.
Things to keep in mind
- Time is your biggest ally. The earlier you start, the more of your number comes from growth rather than your own contributions — so the monthly amount is far smaller.
- Revisit as life changes. A pay rise, a house move or a new baby changes both your spending and your saving capacity; update the inputs rather than treating the number as fixed.
- Fees and pay rises shift the maths. Investment fees raise the monthly amount you need; planning to step up saving as you earn more lowers what you must save today (both modelled in Pro).
- It’s a target, not a finish line. Markets won’t deliver a smooth 7% — you’ll overshoot in good years and lag in bad ones. Aim for the number, then adjust.
Frequently asked questions
Does the number include my state pension?
No — it sizes the pot needed to fund your spending on its own. If you’ll receive a state or workplace pension, your investments only need to cover the gap between that income and your spending, so your personal number can be lower.
What if I’m behind on my number?
You have four levers: save more each month, work a little longer (hugely effective — it adds saving years and shortens the drawdown), spend less in retirement (which lowers the target itself), or accept a slightly higher withdrawal rate. Small moves on several dials beat one heroic effort.
How much do I need to retire?
A common rule is 25× your annual spending (a 4% withdrawal rate). Want €40,000 a year? That’s a €1,000,000 target. Adjust the withdrawal rate for a more conservative or aggressive number.
Why does starting earlier help so much?
Because compounding has more time to work, a larger share of your number comes from growth rather than contributions — so the monthly amount you must save is far smaller. Try moving your age and target age to see it.
Is inflation handled?
Yes — returns are treated as after-inflation, so the number and monthly saving are in today’s money.