UK Pension Pot Projection Calculator — Methodology

Last verified 5 May 2026 against FCA COBS 13 Annex 2 projection rate guidance. Calculator at /uk/pension/pension-pot-projection-calculator/.

What this calculator does

Projects a pension pot value at retirement using compound growth on existing savings plus monthly contributions, with pessimistic, expected, and optimistic scenarios.

The formula

For each year y from now to retirement:
  pot = (pot + annualContribution) × (1 + growthRate)
        × (1 - chargesPct)

Equivalent closed form (constant contributions, end-of-year):
  FV = P₀ × (1+g)^n
     + C × ((1+g)^n - 1) / g

Where:
  P₀  = current pot
  C   = annual contribution (employee + employer + tax relief)
  g   = real growth rate (nominal − inflation)
  n   = years to retirement

Three scenarios are run:
  pessimistic g = 2%
  expected    g = 5%
  optimistic  g = 8%

Authoritative sources

Assumptions and limitations

Growth rates are real (net of inflation); pot value is shown in today's money terms.
Contributions are end-of-year for closed-form calculation; year-by-year iteration assumes annual rebalancing.
Charges are applied as a flat annual percentage of pot value (matching FCA SMPI conventions).
Does not model decumulation (drawdown, annuity, UFPLS) — this is an accumulation-phase tool.
Tax relief on contributions is added separately by the Pension Tax Relief Calculator and not double-counted here.

Source data

The rates used by this calculator are exported as machine-readable CSVs:

Pension allowances 2026/27 /data/pension-allowances-2026-27.csv

These CSVs regenerate automatically from our canonical rate data at every build, ensuring the calculator output and the published rate data stay in sync.

Verification log

5 May 2026: Projection-rate ranges aligned to FCA COBS 13 Annex 2 (2%/5%/8% real)

Try the tool: UK Pension Pot Projection Calculator →