How the calculator works
- Your savings rate: what you don’t spend from your take-home pay is invested each month. Add your pension contributions to your pay, since they’re money you save.
- Your FIRE number: what you’d spend in a year of retirement divided by the withdrawal rate (4% means 25 times your spending).
- Growth: your investments grow at the rate you choose. Everything is in today’s money, so your pay and spending rise with inflation.
Your savings rate sets the timeline
Starting with nothing, with 7% growth, 2.5% inflation and a 4% withdrawal rate:
| You invest | Years to FIRE |
|---|---|
| 10% | 55 |
| 20% | 39 |
| 30% | 29 |
| 40% | 22 |
| 50% | 17 |
| 60% | 13 |
| 70% | 9 |
Your salary doesn’t change these figures. What counts is the share of it you invest.
Example
At 30, with £30,000 invested, £40,000 of take-home pay and £26,000 of spending a year, you invest 35% of your pay. Your FIRE number is £650,000 and you could retire at 53. Spend 10% less, and you could retire at 49.
You’d reach Coast FIRE at about 40: from then on, your investments could grow to your FIRE number by 65 without adding any more.
Bridge years: ISAs before your pension opens
Pensions are the most tax-efficient way to save, with tax relief going in, but you can’t touch them until the minimum pension age: 55 now, and 57 from 6 April 2028. Retire at 53 and you’d have 3½ years, about £89,000 of spending, to cover from elsewhere:
- Stocks and shares ISAs can be used at any age, and what you take out is tax-free. You can put in up to £20,000 a year.
- A general investment account works too, with capital gains and dividend tax on what it earns.
Retire earlier and the bridge grows, so early retirees often split their saving between pensions and ISAs. See what your workplace pension alone could grow to with our pension calculator, or plan your spending with the budget calculator.