Pace of Aging Index — Open Lifestyle-Trajectory Score
A transparent 0–100 lifestyle-trajectory score from habits and simple measures — you versus your own potential, not a biological age.
- Recovery
- 2 cited sources
- Runs in your browser
Your Pace of Aging Index
76 / 100
Pace
0.90
Reduced confidence — some inputs were left blank, so the score is based only on what you entered (53% of the full weighting).
| Input | Score | Weight |
|---|---|---|
| Waist-to-heightT1 · strong evidence | 57 | 23% |
| Activity volumeT1 · strong evidence | 67 | 23% |
| SleepT2 · moderate evidence | 94 | 23% |
| Resting HRT2 · moderate evidence | 75 | 19% |
| SmokingT1 · strong evidence | 100 | 9% |
| AlcoholT2 · moderate evidence | 83 | 4% |
What this is
A transparent lifestyle-trajectory score from modifiable habits and simple measures, with every weight and mapping published. Best read as a set of levers to work on.
What this isn’t
A biological age, a medical test, or a prediction. It cannot tell you how you're ageing at a cellular level, and it isn't validated against health outcomes.
Transparent composite index v1.0.0. It is not a medical test and has not been validated against health outcomes. The full formula, weights and evidence tiers are shown above and in the methodology below.
Methodology
The Pace of Aging Index is an open composite index (v1.0.0) — a transparent 0–100 score summarising how favourable your current lifestyle trajectory looks. It is explicitly not a biological age; it's built from modifiable habits and simple measures, framed as levers you can move.
Each input becomes a 0–100 sub-score (higher = more favourable) via a documented clamped-linear mapping, then combined by weight:
| Input | Weight | Tier |
|---|---|---|
| Cardio fitness (VO₂max) — optional | 25% | T1 |
| Waist-to-height | 12% | T1 |
| Grip strength — optional | 12% | T1 |
| Activity volume (MVPA) | 12% | T1 |
| Sleep | 12% | T2 |
| Resting heart rate | 10% | T2 |
| HRV — optional | 10% | T2 |
| Smoking | 5% | T1 |
| Alcohol | 2% | T2 |
Cardiorespiratory fitness carries the most weight in the design, but our dedicated fitness-age estimate is on hold pending a source we can verify — so VO₂max is optional here (enter a known value, or skip it). Grip and HRV are optional too. Leave any optional input blank and the weights renormalise across what you provided, with a reduced-confidence flag. Full house methodology is on the index methodology page.
The pace number is a centred display of the same index (~0.8 favourable to ~1.2 less favourable) — a display transform, not a hidden model.
Interpreting your result
Look at the radar and sub-scores, not just the headline. They show which habits are lifting or dragging your trajectory — and every one of them is modifiable. A low sub-score is a next step, never a verdict. Body-composition (waist-to-height) is deliberately capped at 12% so the score can never be dominated by, or reward chasing, a single body measurement.
Track your own trend. Because the weights and mappings are fixed and versioned, a change in your score reflects a real change in your habits.
Limitations
- This is a self-tracking construct, not a biological age and not a medical test; it hasn't been validated against health outcomes.
- The sub-score anchors are reasonable but chosen by us and published so you can judge them; different anchors would give different numbers.
- Cardio fitness — the input with the strongest evidence — is optional pending a verifiable source, which lowers confidence when it's omitted.
- It describes lifestyle, not destiny: genetics and circumstance matter enormously and aren't captured here.
Sources
Pull the receipts — 2 cited sources
FitTools · sources
- 01 WHO Guidelines on physical activity and sedentary behaviour, 2020 (150–300 min/week MVPA)
- 02 Ashwell M, Gibson S. Waist-to-height ratio and early health risk (0.5 boundary)
Every formula cited ✓
Frequently asked questions
- Is this my biological age?
- No — deliberately not. It's a transparent lifestyle-trajectory score built from modifiable habits and simple measures. It shows how your current lifestyle stacks up, framed as levers you can change, not a claim about your cells' age.
- What is the 'pace' number?
- A centred display of the same 0–100 index, roughly 0.8 (favourable) to 1.2 (less favourable). It's just another way to read the score — lower suggests a lifestyle trajectory tracking younger. It's a display transform, not a separate hidden model.
- Do I need a VO2max, grip or HRV number?
- No. Those three inputs are optional — enter them only if you know them from a test or wearable. Leave them blank and the score renormalises across what you did provide, flagging reduced confidence. It never guesses a value.
- Why is cardio fitness optional here?
- Cardiorespiratory fitness carries real weight in the methodology, but our dedicated fitness-age tool is on hold pending a source we can verify. Rather than estimate it unreliably, we let you enter a known VO2max or skip it.
- Is this a medical test?
- No. It's a transparent self-tracking index, not validated against health outcomes and not a diagnosis. Everything is computed in your browser.
Written and reviewed by Mathew Beale — MSc Biotechnology, University of Reading.
Last reviewed:
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