Helixspan estimates your projected healthspan — the years you'll likely live in good health — from a handful of modifiable inputs. Move the sliders and watch your score update in real time.
The single largest modifiable risk factor. Current smokers lose up to 8 healthy years versus never-smokers. Former smokers who quit before age 40 recover nearly all of the deficit within a decade.
BMI has a U-shaped relationship with healthy life expectancy. Risk is lowest at BMI 22–25. Both underweight (<18.5) and severe obesity (>35) carry meaningful reductions in healthspan.
Regular physical activity is the strongest positive lever in the model. Even 30 minutes of moderate exercise per week shows measurable benefit; gains continue up to roughly 300 minutes per week.
Sleep follows a U-shaped mortality curve. The optimal window is 7–8 hours per night. Chronic short sleep (<6 h) and long sleep (>9 h) are both associated with elevated all-cause mortality in large population studies.
Scored on a Mediterranean-style index. A high-quality diet rich in vegetables, legumes, whole grains, fish, and olive oil — low in ultra-processed foods — is associated with up to 2 additional healthy years versus a poor diet.
Risk rises beyond roughly 7 standard drinks per week. Heavy drinking above 14 units per week is associated with up to 5 fewer healthy years, driven by elevated risk of liver disease, cardiovascular events, and several cancers.
Sustained psychological stress elevates cortisol and inflammatory markers linked to accelerated biological aging. The effect is moderate — around 1–2 years — but compounds over decades of chronic exposure.
The Helixspan score is a 0–100 composite of seven modifiable lifestyle factors, anchored to WHO Healthy Life Expectancy data for high-income populations. A score of 72 represents the population baseline.
Score bands: At risk (below 50) · Fair (50–64) · Strong (65–79) · Excellent (80 and above).
Enable JavaScript to use the interactive calculator and get your personalised estimate.
Helixspan is intentionally simple. A handful of inputs you can verify, weights derived from longitudinal cohorts, and a score that's open about its assumptions.
We anchor on WHO's Healthy Life Expectancy (HALE) at birth for high-income populations — roughly 70 years for men and 73 for women — and adjust from there. HALE is the share of life spent in good health, not total lifespan.
Weights are derived from cohort studies of behaviour-attributable mortality (Li et al. 2018, GBD 2019, UK Biobank meta-analyses). Lifestyle factors plausibly explain a 10–14 year range in healthy life expectancy.
The 100-point score is a rescaled version of the same modifiers, centred at 72. It's a comparative readout, not a clinical risk number. Bands: at risk → fair → strong → excellent.
| Factor | Plausible range (years) | Relative weight | Direction |
|---|---|---|---|
| Smoking | −8 to 0 | negative | |
| BMI | −7 to 0 | U-shaped | |
| Alcohol | −5 to 0 | negative | |
| Exercise | −4 to +3 | positive | |
| Sleep | −4 to +2 | U-shaped | |
| Diet quality | −3 to +2 | positive | |
| Stress | −2 to +1 | positive |
Helixspan is a simplification of population research. The studies below are where the weights and ranges come from. They are imperfect — observational, mostly Western cohorts — and the score is a guide, not a diagnosis.