GeraCash / Pension & Retirement Calculator / Methodology
Gera Retirement Readiness Score — Methodology
A fully reproducible, public formula computed from DWP and ONS published rates. Every input traces to an official, OGL-licensed UK government source. No estimated or fabricated numbers.
What is the Gera Retirement Readiness Score?
The Gera Retirement Readiness Score (GRRS/100) is a Gera-computed index that measures how closely a saver's projected annual retirement income meets the standard 70%-replacement target — the benchmark used by DWP and the pensions industry for adequacy. A GRRS of 100 means the projected income fully meets or exceeds the target; lower scores indicate a gap.
GRRS is NOT a guaranteed income prediction. It is a deterministic projection based on published DWP and ONS constants (contribution rates, state pension, growth rate assumption) applied to a parametric grid. Real outcomes depend on actual fund performance, contribution history, salary changes, and tax changes. For personalised regulated advice, consult a FCA-authorised financial adviser.
Formula (reproducible)
# Step 1: Qualifying earnings
QE = max(0, min(gross, 50,270) − 6,240)
# Step 2: Annual pension contribution
annual_contrib = QE × total_contrib_rate // min 8% = 3% employer + 5% employee
# Step 3: Future value of contributions (FV annuity)
r = 0.035 // DWP real growth rate assumption (CPI-adj)
n = 67 − current_age // years to retirement
pot = annual_contrib × ((1 + r)^n − 1) / r
# Step 4: Annual drawdown
drawdown = pot / 15 // ONS life expectancy (82 − 67 = 15 yr)
# Step 5: Total annual retirement income
state_pension = 11973 // £230.25/week × 52 — DWP 2025-26
total_income = drawdown + state_pension
# Step 6: GRRS
target = gross × 0.7 // 70% replacement rate — DWP benchmark
GRRS = min(100, round(total_income / target × 100))
Published input rates — 2025–26 (exact values)
| Parameter | Value | Source |
|---|---|---|
| Full new State Pension (weekly) | £230.25/week | DWP 2025–26 |
| Full new State Pension (annual) | £11,973/yr | £230.25 × 52 |
| Auto-enrolment: employer minimum | 3% | Gov.uk (from April 2019) |
| Auto-enrolment: employee minimum | 5% | Gov.uk (from April 2019) |
| Qualifying earnings — lower limit | £6,240/yr | Gov.uk 2025–26 |
| Qualifying earnings — upper limit | £50,270/yr | Gov.uk 2025–26 |
| DWP real growth rate assumption | 4% p.a. (CPI-adj) | DWP pension modelling technical annex (OGL v3.0) |
| Replacement rate target | 70% | DWP adequacy benchmark |
| State Pension age | 67 | Pensions Act 2014 |
| ONS average life expectancy at birth | 82 years | ONS 2017-19 (OGL v3.0) |
| Drawdown period | 15 years | 82 − 67 = 15, minimum 15 |
Worked example
Age 35, salary £35,000, 8% contribution (statutory minimum)
1. Years to retirement: 67 − 35 = 32 years
2. Qualifying earnings: min(£35,000, £50,270) − £6,240 = £28,760
3. Annual contribution: £28,760 × 8% = £2,301/yr
4. Projected pot: FV(£2,301, 4%, 32 yr) = £131,927
5. Annual drawdown: £131,927 ÷ 15 = £8,795/yr
6. State pension: £230.25/week × 52 = £11,973/yr
7. Total income: £8,795 + £11,973 = £20,768/yr
8. Target income: £35,000 × 70% = £24,500/yr
9. GRRS: min(100, round(£20,768 / £24,500 × 100)) = 85 / 100
GRRS bands
GRRS 90–100 — Strong
Projected income meets or exceeds the 70%-replacement target.
GRRS 70–89 — Good
On track. A small increase in contributions would close any gap.
GRRS 50–69 — Moderate
Covers a substantial share; higher contributions or earlier start recommended.
GRRS <50 — Poor
Projected income falls significantly below target. Action is advisable.
What the GRRS does NOT include
- Salary growth: Contributions are constant in real terms — a conservative baseline. Real salary growth would increase the actual pot.
- Existing pension pots: The GRRS models contributions from the current age only. Pre-existing pots would improve readiness.
- Variable annuity rates: We use level drawdown (pot ÷ 15 yr). Actual annuity rates vary with gilt yields.
- Defined benefit / final salary pensions: Only DC (defined contribution) auto-enrolment pots are modelled.
- Tax relief on contributions: Basic-rate tax relief is not explicitly modelled; in practice, employee contributions receive income tax relief, increasing effective pot size.
- Partial NI records: Full state pension (35 qualifying years) is assumed. A partial record gives a lower state pension proportionally.
- Investment risk: The 4% real growth rate is a central estimate. Actual fund performance varies.
Data sources
Contains public sector information published by Department for Work and Pensions (DWP) and licensed under the Open Government Licence v3.0. Source: DWP — Benefit and pension rates 2025 to 2026 (2025–26, published April 2025).
Contains public sector information published by Department for Work and Pensions (DWP) and licensed under the Open Government Licence v3.0. Source: GOV.UK — Workplace pensions: what you, your employer and the government pay (April 2019 onwards (current), published April 2019).
Contains public sector information published by Office for National Statistics and licensed under the Open Government Licence v3.0. Source: ONS — Annual Survey of Hours and Earnings (ASHE) 2025, provisional (April 2025 (provisional), published 23 October 2025).
Contains public sector information published by Office for National Statistics and licensed under the Open Government Licence v3.0. Source: ONS — Life expectancy by local authority (2017-19) (2017-19, published 9 November 2020).