Data Source and Methodology
Contribution growth is modelled using standard future value of an annuity formulas. Withdrawal estimates rely on the inflation-adjusted annuity formula recommended by the UK MoneyHelper pension calculator and US CFP® guidance for sustainable drawdown ranges (3%–5% real).
All calculations are strictly based on the formulas and data provided by these sources.
Key Formulas
Future value of contributions
Total balance
Inflation-adjusted monthly income
Glossary
- Net return: Gross return minus annual fees.
- Contribution frequency: How often you deposit into the pension.
- Inflation assumption: Used to translate future values into today’s money.
- Withdrawal horizon: Number of years you expect the pension to last in retirement.
Frequently Asked Questions
How realistic are the return assumptions?
Use long-term average returns for your asset mix, then subtract the total expense ratio of your pension funds to estimate net return.
Can I model a lump-sum withdrawal?
Yes. Set the payout horizon to 1–5 years and review the monthly income figure—it represents the fixed payment needed to spend down the pot.
How should I treat employer contributions?
Add the expected employer match per contribution period. The calculator treats it as additional, guaranteed deposits.