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Calculator Retirement · No. 09

Drawdown sustainability

How long could a pension pot last? Model withdrawals, growth and inflation and find the depletion age.

Your data
Stays in your browser
Method
Stated in full — § 04
Companion guide
Retirement income options
Status
Illustration — not a recommendation
Inputs Your numbers § 01
Result Under these assumptions § 02

Explanation What the number means § 03

Each year the pot grows at the assumed rate, then a year of income is withdrawn.

Each year the pot grows at the assumed rate, then a year of income is withdrawn. The income rises with inflation, so the pot must work harder every year. When the balance hits zero, that is the depletion age.

This is a smooth-return model. Real drawdown is exposed to sequencing risk — poor returns early, combined with withdrawals, can exhaust a pot that average returns say should survive.

Assumptions Method, stated in full § 04

Formula

potₜ₊₁ = potₜ(1 + g) − income × (1 + i)ᵗ

g assumed growth, i inflation, t years since drawdown began. Stops at age 100.

  1. 01Smooth annual returns; no volatility or sequencing risk.
  2. 02Income withdrawn once a year, after growth.
  3. 03No tax on withdrawals, no charges, no State Pension or other income.
  4. 04Inflation applied to income only, not to a target standard of living.
Sensitivity What changing one variable does § 05

Holding everything else at your inputs

Each row changes one variable and shows the result. It illustrates which assumptions the answer is most sensitive to — it does not suggest which to choose.

VariableChanged toLasts to agevs your result

Reminder: this tool is general education. It doesn't know your circumstances, can't see future markets, and isn't a personal recommendation. Retirement income decisions are complex and largely irreversible: use Pension Wise (free, from 50) and consult an FCA-authorised adviser — our toolkit shows how to find one.