How to Use the State Pension Forecast & Gap Calculator

This free UK calculator estimates the new State Pension you may get from your National Insurance record, what missing years could cost to fill, and how large a private or workplace pension you still need to reach a chosen retirement income. Figures use 2026/27 rates. It is not the official forecast and is not financial advice.

Step-by-Step Guide

1. Start with your official forecast

Get your qualifying years and personal forecast from gov.uk/check-state-pension. Enter that number here. The government tool is the only place that applies starting amounts and any contracted-out deduction from before April 2016.

2. Enter date of birth and planned retirement age

The calculator works out your State Pension age from the Pensions Act timetable (66, the 2026–28 step-up, 67, or the planned 68). If you plan to stop work before that age, set Planned retirement age lower to see the pre-State Pension gap — the years you must fund entirely from private savings.

3. Add years you will still earn, and years you might buy

Each qualifying year is worth 1/35 of the full new State Pension. You usually need 10 years to get anything and 35 for the full rate. Extra years above 35 do not increase the new State Pension. Voluntary Class 3 contributions cost £18.40 a week in 2026/27 (£956.80 a year). Self-employed people who can pay Class 2 instead use the toggle (£3.65 a week).

SP = 0 if Y < 10, else min(Y, 35) ÷ 35 × £241.30 a week

4. Choose a household target

Pick a Pensions UK / PLSA 2026 living standard for a single person or a couple, or type a custom annual income. Couple figures are household totals. Optionally include a partner’s State Pension. PLSA amounts exclude rent and mortgage payments.

5. Project the private pension gap

Enter your current pot, monthly contributions, an assumed investment return and a withdrawal rate (4% is a common rule of thumb for a pot that needs to last around 30 years). The calculator grows the pot to your planned retirement age, funds any pre-SPA years, then compares remaining drawdown plus State Pension with your target.

Extra pot ≈ max(0, Target − household SP − private drawdown) ÷ withdrawal rate

Common Scenarios & Examples

Scenario: On track for almost the full State Pension, but a large lifestyle gap

Goal: See whether a modest workplace pot plus the new State Pension covers a moderate single retirement.

Date of birth 1 January 1970 (State Pension age 67).
25 qualifying years so far, 8 more years still to earn, 0 years bought.
Target: PLSA moderate, single (£32,700).
Pot £50,000, £250 a month, 5% return, 4% withdrawal, retire at 67.

What the maths does:

33 qualifying years → 33/35 × £241.30 ≈ £227.51 a week (about £11,831 a year).
Income still needed from private pensions: £32,700 − £11,831 ≈ £20,869 a year.
Pot that 4% drawdown would need at 67: about £522,000.
The current £50,000 + £250 a month at 5% falls well short — the extra monthly saving figure shows the scale of the gap.

Scenario: Buying two missing years

Goal: Check whether Class 3 top-ups are worth it if you would otherwise finish on 33 years.

Keep 25 years held and 8 still to earn.
Set missing years you may buy to 2.
Leave Class 3 selected.

Rule of thumb at 2026/27 rates:

Two Class 3 years cost 2 × £956.80 = £1,913.60 and add about 2 × £358.50 = £717 a year for life. Simple payback is a little under three years of receiving the higher pension — if those years actually increase your forecast. Always confirm gaps and deadlines on GOV.UK.

Scenario: Retiring at 60 before State Pension age

Goal: Size the pre-SPA gap as well as the usual post-SPA shortfall.

Set planned retirement age to 60 (SPA remains 67 in the default example).
Read the pre-State Pension gap box: seven years must be funded from the pot before any State Pension is paid.
The pot path then falls during those years as you draw your target income, leaving less for 4% drawdown after 67.

What this calculator assumes

New State Pension rules only (State Pension age on or after 6 April 2016).
A constant 2026/27 full rate of £241.30 a week. Triple lock increases after you claim are not projected.
No contracted-out deduction and no pre-2016 starting amount — use the official forecast for those.
Voluntary NI is modelled at current Class 2 or Class 3 weekly rates × 52. Eligibility and the six-year look-back are not checked.
Private pot growth uses monthly compounding at your stated return, with no fees or tax relief modelled.
From planned retirement until State Pension age, the pot is assumed to pay the full target income. After State Pension age, private income is remaining pot × withdrawal rate.
PLSA figures are after-tax spending and exclude housing costs.

Disclaimer & Limitations

Not official and not advice: This page is an educational estimate. Your legal entitlement comes from your National Insurance record and is shown on Check your State Pension. It does not constitute financial, tax or pensions advice. Consider a regulated adviser or Pension Wise (MoneyHelper) before acting.

Contracting out and starting amounts: If you paid NI before 6 April 2016, especially if you were contracted out of Additional State Pension, your forecast may not equal years ÷ 35 × £241.30. This tool omits that deduction.

Old State Pension: Men born before 6 April 1951 and women born before 6 April 1953 fall under the old basic / Additional State Pension. The numbers here are illustrative only for those cohorts.

Investment and longevity risk: Returns are not guaranteed. A 4% withdrawal rate is a rule of thumb, not a promise the pot will last. Inflation, fees, tax, annuity rates and Pension Credit can all change the real outcome.

Bug Reports and Suggested Improvements

Please email suggestions and bug reports to: statepensioncalc@personalfinances.me, thank you.

State Pension Forecast & Gap Calculator

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