The double lock just changed your number — here's what to do about it
In October 2026 the government announced the UK State Pension triple lock will become a double lock from 6 April 2030. The current formula — the highest of CPI inflation, average earnings growth, or 2.5% — drops the earnings leg. The new rule is the highest of CPI inflation or 2.5%. That single change removes the mechanism that has historically pushed the State Pension up faster than prices alone.
The reform is intended to fund a National Care Service through ~£15bn a year of saved uprating by 2040. That is a genuine trade-off — this is not a simple cut. It is also the reason the reform is happening. Existing pensioners are protected through the parliamentary term. Everyone who reaches State Pension age on or after 6 April 2030 is on the new formula.
This calculator does one job: it shows you the personal impact in pounds. Enter your current age, target retirement age, pension pot, contributions, and the State Pension amount you actually expect to receive (the £12,548 default is the 2026/27 full new State Pension; use less if your NI record is incomplete). The calculator projects your private pot forward at a 4% real return, then projects your State Pension under each regime — the current triple lock (3.89% per year) and the post-2030 double lock (modelled at the 2.5% floor).
The headline number is the annual gap in State Pension income at retirement. The second number is the cumulative cost over a 25-year retirement. The third number — “your number” — is the additional private pension pot you would need today to close the gap, plus the equivalent monthly contribution for the years you have left.
For most people 10–20 years out, the cumulative figure is in the tens of thousands. The earlier you check, the more years you have to spread the additional contributions, and the smaller the monthly hit. If the calculation moves your number materially, adjust your plan: increase pension contributions, redirect ISA savings into your pension, or check whether voluntary Class 3 National Insurance contributions would top up your State Pension forecast.
Run the calculation, then adjust your plan. For a full 50-year projection with this scenario, open the UK FIRE calculator — the same scenario toggle lives there and lets you see the long arc of the reform, not just the annual gap.