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Life Expectancy At Birth Calculator

Work out life expectancy at birth instantly with clear inputs, formula shown and shareable results.

About Life Expectancy At Birth Calculator

Applies the life table identity linking life expectancy at birth to infant mortality and life expectancy at age one.

Formula

Life table identity

e0 = q0 x a0 + (1 - q0) x (1 + e1), where q0 is infant mortality, a0 the average years lived by infants who die and e1 life expectancy at age one

Worked example

With the default values below, Life Expectancy At Birth Calculator returns Life expectancy at birth of 71.546. Change any input above and every figure here is recalculated in your browser.

Inputs used

Infant mortality rateaccepts 0.1–300 per 1000 live births
20 per 1000 live births
Life expectancy at age oneaccepts 5–100 years
72 years
Average years lived by infants who dieaccepts 0.05–1
0.3

Results

Life expectancy at birth
71.546 years
Years of expectancy lost to infant mortality
1.454 years
Survivors to age one per 1,000 births
980.0
Infant mortality as a fraction
0.02000

Step by step

  1. 1Values used
  2. 2Life table identity
  3. 3Life expectancy at birth= 71.546 years
  4. 4Years of expectancy lost to infant mortality= 1.454 years
  5. 5Survivors to age one per 1,000 births= 980.0
  6. 6Infant mortality as a fraction= 0.02000

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax or compounding frequency into account.
  • Figures are rounded for display to 5 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why does infant mortality dominate life expectancy?

An infant death removes a full lifetime from the average, which is why historical gains came largely from child survival.

Is this period or cohort expectancy?

Period expectancy, since it applies current mortality rates rather than projecting future improvement.

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