Helixspan is published by Healthworks. We are interested in healthspan — the years people live in good health rather than simply the years they live — and this calculator is our attempt to make that idea concrete enough to act on.
Healthworks is an independent project dedicated to healthspan and longevity — specifically, to making the research on modifiable health factors legible to people who aren't going to read the underlying papers. We believe the gap between how long people live and how long they stay well is the most under-discussed number in public health, and that most people have never seen it quantified for their own circumstances.
We should be equally clear about what we are not. Healthworks is small and self-funded. It is not a clinic, a medical practice, a research institution, or a health company. We do not employ physicians or clinical researchers, and the guides on this site are not reviewed by one. Our work is the synthesis and explanation of published population research — not original research, and not clinical expertise.
We state that plainly because health content deserves scepticism, and because a project that invented credentials it didn't have would deserve more of it. Everything we publish carries its sources, its dates, and an honest label about what reviewed it. The editorial standards page sets out exactly how we source claims and what we refuse to do.
Healthspan — the years you live in good health, free from serious chronic disease or disability — matters more to most people than raw lifespan. Yet most online calculators either hide their methodology or overstate their precision.
Helixspan takes a different approach. Every weight is published on the homepage. The assumptions are stated plainly. The limitations are front and centre. The score is a guide for reflection, not a clinical risk assessment — and the Learn guides walk through the evidence behind each factor, including where that evidence is weak.
Every factor weight is published on the homepage. The methodology page explains exactly how the score is calculated, and citations link to open-access studies.
Your inputs never leave your browser. No account, no tracking, no server receiving your health data. Everything runs locally in JavaScript.
Weights are drawn from large population studies — GBD 2019, Li et al. 2018, UK Biobank meta-analyses, and WHO HALE data. Sources are cited for every factor.
The model is a deliberate simplification. It doesn't capture genetics, medications, access to care, or dozens of other factors that influence real health outcomes.
Most people know that smoking is bad and exercise is good. The difficulty is turning that abstract knowledge into a felt sense of consequence. Helixspan tries to close that loop — not by moralising, but by showing a plausible range of outcomes as you move the sliders.
The immediate, real-time feedback from adjusting an input is deliberately designed to make the relationship between habit and outcome visceral rather than statistical.
It is a tool for reflection, not a diagnostic instrument. Use it alongside conversations with your doctor, not instead of them.
The Helixspan model has three components, each documented in full in the methodology section of the homepage.
We start from HALE at birth for high-income populations — roughly 70 years for men and 73 for women — and add or subtract years based on lifestyle inputs. HALE measures years lived in good health, not total lifespan.
Each of the seven factors contributes a year delta drawn from the plausible ranges published in the source studies. The total possible range spans roughly −14 to +3 years relative to the population baseline.
The raw healthspan estimate is rescaled to a 0–100 score centred at 72 — the population average for high-income countries. Bands: At risk (below 50) · Fair (50–64) · Strong (65–79) · Excellent (80+).