Health Factor Scoring
How we quantify the health assets you build
Overview
Your health score combines three factors: your health assets (H), your risks (R) and your chronic conditions (C). This post covers H, the factor that raises your score: the habits and circumstances that support good health.
H runs from 0 (no health assets) to 1 (every component at its best). It is a weighted sum of eight components, each also scored from 0 to 1:
\[ H = \sum_{i=1}^{8} w_i \, a_i \qquad \text{with} \qquad \sum_i w_i = 1 \]
Updated October 2026 for scoring model v0.2.0. An earlier version of this post described v0.1.0.
The eight components
| Component | Weight | What we ask about |
|---|---|---|
| Physical activity | 20% | Whether you exercise, how many days a week, and for how long |
| Socioeconomic security | 15% | Your income source and any financial concerns |
| Sleep | 15% | Hours of sleep a night |
| Nutrition | 15% | Whether you eat a balanced diet |
| Education | 10% | Your highest level of education |
| Immune system | 10% | Vaccination status and allergies |
| Perceived wellness | 10% | How you rate your own health, from 1 to 5 |
| Mental health | 5% | Any mental health conditions, current or past |
The weights are our starting assumptions. We will revisit them as scores and outcomes come in.
Physical activity (20%)
We multiply days a week by hours a session to get weekly hours. The WHO recommends 2.5 to 5 hours of moderate activity a week.
| Weekly hours | Score |
|---|---|
| 3.5 or more | 1.0 |
| 2.5 to 3.5 | 0.83 |
| 1.5 to 2.5 | 0.67 |
| 0.5 to 1.5 | 0.50 |
| Less than 0.5 | 0.33 |
| None | 0.17 |
Not exercising at all scores 0. If you used to exercise but don’t now, you keep 10% of the score your past routine would earn.
Socioeconomic security (15%)
The average of two answers. Income: active income 1.0, income from family or friends 0.67, no income 0.33. Financial concerns: none 1.0, some 0.67, very concerned 0.33.
Sleep (15%)
| Hours a night | Score |
|---|---|
| 8 to 9 | 1.0 |
| 7 to 8 | 0.95 |
| 6 to 7 | 0.75 |
| 5 to 6 | 0.50 |
| 3 to 5 | 0.25 |
| Less than 3, or more than 9 | 0.10 |
Regularly sleeping more than 9 hours is, for an adult, as much a warning sign as sleeping too little, so we score it low. We will revisit this weighting as scores come in.
Nutrition (15%)
A balanced diet scores 1.0, unsure 0.6, and no 0.3.
Education (10%)
From 0.17 (elementary or primary) through 0.33, 0.50, 0.67 and 0.83 to 1.0 (PhD or professional degree). Education is linked to health literacy and access to preventive care.
Immune system (10%)
Vaccinated 1.0, not vaccinated 0.3. Allergies reduce this by 20%, as a sign of an immune system under extra load.
Perceived wellness (10%)
Your own 1–5 rating divided by 5. How people rate their own health is a strong predictor of future health.
Mental health (5%)
This starts at 1.0 and is reduced by each condition you report. Each condition’s reduction is its prevalence times its severity, for your sex. A condition you had in the past counts at 25%.
How H shapes your score
Your score follows a curve over your lifetime:
\[ \text{score}(\text{age}) = -\alpha R \cdot \text{age}^2 + \beta H \cdot \text{age} + \gamma C \]
H sets how steeply the curve rises: more health assets mean a higher peak, reached later. The parameters α, β and γ were calibrated in January 2026. Most scores fall between 0 and 100; a very healthy profile can score above 100.
Validation
The model was calibrated on a set of test surveys. It has not yet been validated against clinical outcomes; we plan to do that as real scores accumulate.
Open source
The scoring code is open source under the MIT licence: github.com/preacterik/preact-health-scoring. Review it, suggest improvements, or contribute.
References
- World Health Organization. Guidelines on physical activity and sedentary behaviour (2020).
- Hirshkowitz M, et al. National Sleep Foundation’s sleep time duration recommendations. Sleep Health (2015).
- US Department of Agriculture and HHS. Dietary Guidelines for Americans, 2020–2025.
- CDC. Social determinants of health.