Methodology
How the numbers are produced
Every quantitative surface on this site reads from one validated dataset, so a source update cannot leave two pages disagreeing. This page explains where the data comes from and what it can and cannot support.
WHO Global Health Observatory
Published life tables and healthy life expectancy indicators.
Validation on download
Records checked and invalid rows dropped; provenance kept with the values.
One validated dataset
The single source every quantitative page reads from.
The page you see
Published values displayed with source, data year and method.
No step adds an estimate, interpolation or adjustment of its own.
Source hierarchy
Swipe the table sideways to see all columns.
| What | Source | Data year | Indicators / basis |
|---|---|---|---|
| Mortality and life tables | WHO Global Health Observatory — life tables by country | 2021 | LIFE_0000000031 (lx) — https://ghoapi.azureedge.net/api/LIFE_0000000031; LIFE_0000000035 (ex) — https://ghoapi.azureedge.net/api/LIFE_0000000035 |
| Healthy life expectancy | WHO Global Health Observatory — Global Health Estimates | 2021 | WHOSIS_000001 — life expectancy at birth; WHOSIS_000015 — life expectancy at age 60; WHOSIS_000002 — healthy life expectancy (HALE) at birth; WHOSIS_000007 — healthy life expectancy (HALE) at age 60 |
| Factor evidence | Peer-reviewed literature and major health institutions | Varies | Systematic reviews, meta-analyses, large cohort studies, and randomised trials where they exist. |
Life tables retrieved 2026-09-09; healthy life expectancy retrieved 2026-09-09. The retrieval date is not the data year.
UN World Population Prospects is a comparable authority for mortality. It is not used in this build; if it is added later, it will appear behind the same data layer with its own provenance shown.
Country coverage
185 countries and areas: the 183 WHO Member States with a population of at least 90 000, plus Puerto Rico and the occupied Palestinian territory. The eleven Member States below the population threshold (Andorra, Cook Islands, Dominica, Marshall Islands, Monaco, Nauru, Niue, Palau, Saint Kitts and Nevis, San Marino, Tuvalu) are not published in this release and are therefore absent here.
In plain English
- Life table
- A table that converts observed age-specific death rates into survivors and expected further years of life at each age.
- Abridged life table
- A life table grouped into five-year age bands rather than single years, ending here at the 85+ band.Why it matters: It sets the limit of what this site can show: no single-year ages, and no survival to 90 or 100.
- HALE
- Healthy life expectancy: expected years of life with time in illness or disability discounted by estimated severity.
Life expectancy
A life table converts observed age-specific death rates into the number of survivors at each age and the expected further years of life at each age. The figure quoted at birth is the average further years for a newborn under that year's rates.
Remaining life expectancy
The Explorer reports the published ex value for the age band containing the age you choose. WHO publishes abridged tables in five-year bands, so a chosen age is mapped to its official band and shown as such. Nothing is interpolated to a single year of age.
Survival probability
The chance of reaching a later age is the ratio of the published survivor count at that age to the survivor count at the starting age band. It is a direct ratio of two published numbers.
Healthy life expectancy
HALE adjusts life expectancy for years lived in less than full health, weighted by the severity of health states in the Global Health Estimates.
WHO publishes HALE at birth and at age 60. SnapLongevity compares life expectancy with HALE only at those two ages, from the same source and the same year. It never subtracts HALE at birth from remaining life expectancy at another age, because the result would not mean anything.
Data year versus update date
The data year is the year the estimate refers to — 2021 for life tables and 2021 for healthy life expectancy. The retrieval date is when the values were downloaded. Neither is the date the page was edited, and a recent page edit never means a recent estimate.
Why sources disagree
Different agencies use different input data, different reference years and different modelling for countries with incomplete death registration. A national statistics office and WHO can both be correct and still publish different figures for the same country. Any comparison here uses one source at a time.
Evidence standards for factors
- Randomised trials outrank cohort studies where they exist and are relevant.
- Associations are described as associations, never as guaranteed years gained.
- Animal and biomarker findings are not converted into human lifespan claims.
- Uncertainty is stated in the article rather than buried in a disclaimer.