UK Pension Calculator

How the calculation works

The calculator is rules-based, not Monte Carlo. For each future year between now and your projected State Pension Age, it applies the current statutory rules (NI thresholds, Annual Allowance, employer-match minimums, qualifying-earnings band) and your stated contribution split to a deterministic projection. It uprates the State Pension by an explicit assumption you choose (default: the long-run triple-lock average) and grows the workplace pot at a default 5% real return — these are explicit assumptions you can change.

The output is not a forecast of any specific outcome. It is a transparent walkthrough of the maths under your inputs. Every figure can be checked against the underlying rule, and every rule citation links back to the source — DWP rate-uprating order, HMRC Pensions Tax Manual paragraph, MoneyHelper guidance article, or FCA Handbook reference.

Inputs we ask for

Three required inputs and three optional:

• Year of birth — determines State Pension Age (66 today; rising to 67 between April 2026 and March 2028; 68 between 2044 and 2046)
• Current gross salary — determines which Annual Allowance applies (standard £60,000 or tapered for £260,000+ adjusted income), tax band, and qualifying-earnings band
• Workplace contribution split — your % and employer %, including any matching arrangement above auto-enrolment minimums
• Optional: existing pension pot value (workplace DC and any historical SIPP/personal pension consolidated value)
• Optional: NI qualifying years to date (from your gov.uk State Pension forecast — defaults to a current-age-minus-22 estimate if unknown)
• Optional: SIPP contribution above workplace — for higher-rate taxpayers consolidating or topping up

Privacy and what we don't do

All inputs are private and run on-device. No server-side storage, no account requirement, no email capture, no upsell to a regulated adviser. The calculator output stays in your browser. PlainPension does not, and will not, monetise calculator inputs by linking them to identifiable individuals, profile them for advertising, or share them with any third party.

The only place data leaves your browser is the Google AdSense ad request — which uses Consent Mode v2 and asks for your explicit permission on first visit. If you do not consent, ads still load but with no personalisation signals. If you do consent, the ad request shares standard contextual signals (page URL, language, device class) and any consent-gated identifiers — but no calculator inputs.

Limitations

The calculator covers typical UK saver scenarios — auto-enrolled employees, self-employed sole-traders, higher-rate taxpayers consolidating workplace pots into a SIPP. It does not cover: Defined Benefit transfers above £30,000 (which by law require regulated advice); contracted-out NI history pre-April 2016 (where the “starting amount” calculation can differ from the simple 35/35 reckoner); lifetime allowance protections (FP2012, FP2014, FP2016, IP2014, IP2016); or overseas residence rules under bilateral Social Security agreements. For any of these, use the free MoneyHelper Pension Wise service or consult an FCA-regulated independent financial adviser.

Where the numbers come from

Every rate, allowance, and rule the calculator applies is sourced from a single canonical reference: the DWP rate-uprating order (for State Pension weekly rates and qualifying-year thresholds), the HMRC Pensions Tax Manual (for Annual Allowance, taper, MPAA, and lump-sum allowance), MoneyHelper's pension hub (for plain-language interpretations), and the FCA Register (for regulated pension providers). The full sourcing chain is in our methodology page.

Launch date

The interactive calculator is in active development and launching in an upcoming release. In the meantime, the rate history research, wrapper comparison, and voluntary NI break-even pages cover the three calculations savers most often run by hand. The guides walk through the rules.

PlainPension is for informational purposes only and does not provide financial, tax, or pension advice. Calculator results are deterministic projections based on the inputs and assumptions you enter — they are not a forecast of any specific outcome. Consult an FCA-regulated adviser or use MoneyHelper's free Pension Wise service before making material pension decisions.