How it works
Enter your current age, retirement age, savings and monthly contribution. The calculator compounds them at your expected return, then applies the 4% rule to estimate a sustainable monthly income.
Future value = savings × (1+r)ⁿ + monthly × ((1+r)ⁿ − 1) ÷ r
The 4% rule
- Withdraw about 4% of your pot each year in retirement.
- A pot of 1,000,000 suggests roughly 40,000 a year.
- It is a guide, not a guarantee — returns and inflation vary.
Standards and sources
- 4% rule (Trinity study–style safe withdrawal rate)
- Standard future-value formula with monthly compounding
- For reference only, not financial advice
Last reviewed October 8, 2026
Frequently asked questions
What is the 4% rule?
It is a common guideline that you can withdraw about 4% of your pot each year in retirement. A 1,000,000 pot suggests around 40,000 a year, or about 3,333 a month.
How is the projection calculated?
Monthly compounding at a constant return: your current savings grow, and each monthly contribution grows too. Real returns vary year to year.
How much should I contribute?
There is no single answer — the more you contribute and the earlier you start, the more compounding helps. Aim for a realistic return, not an optimistic one.