A Disability-Adjusted Life Year (DALY) is a measure of overall disease burden. One DALY represents one year of healthy life lost — either through premature death (YLL) or through living with disability or illness (YLD). DALYs are used by WHO, the World Bank, and GBD researchers to compare burden across diseases and populations.

What is the difference between YLL and YLD?

YLL (Years of Life Lost) counts life-years lost due to premature death, calculated as deaths × remaining life expectancy. YLD (Years Lived with Disability) counts life-years lost to non-fatal illness, calculated as incidence × disability weight × average duration.

What disability weight should I use?

Disability weights range from 0 (perfect health) to 1 (equivalent to death). The Global Burden of Disease study publishes standardized weights for hundreds of conditions — for example, mild hearing loss ≈ 0.02, severe depression ≈ 0.66, terminal cancer ≈ 0.54. Use the GBD disability weight database for published estimates.

Does this tool apply age-weighting or discounting?

No. Modern GBD methodology (post-2010) dropped age-weighting and time-discounting. This calculator uses the current standard: uniform weights across all ages, no discounting. If your study requires the older DALY formulation with age-weighting and 3% discounting, adjust your inputs accordingly.

What life expectancy standard should I use for YLL?

GBD uses a reference standard life expectancy (currently the Global Health Life Table 2019 values). A common simplification is to use 86 years (the highest observed life expectancy) minus the age at death, or to pull age-specific values from the GBD supplementary data.

How do I interpret DALYs per 100,000?

The rate normalizes burden to population size, enabling fair comparisons between countries or regions of different sizes. A rate of 500 DALYs per 100,000 means the disease costs the equivalent of 500 healthy life-years for every 100,000 people in the population each year.

DALY Calculator

Name: DALY Calculator
Availability: InStock
Author: Nham Vu

Calculate DALYs by entering YLL and YLD values, or compute each component from raw epidemiological inputs.

Calculation mode

Enter YLL & YLD directly

Compute from components

Direct inputs

Years of Life Lost (YLL)

Years Lived with Disability (YLD)

Population size (optional, for rate)

Enter values and click Calculate DALYs to see the results.

Total DALYs

Breakdown

Component	Value	% of DALYs
YLL (mortality)	—	—
YLD (disability)	—	—
Total DALYs	—	100%

Composition

YLL (mortality) YLD (disability)

Formula used: DALY = YLL + YLD

No age-weighting or time-discounting (GBD 2010+ standard).

Summary

Calculate DALYs by entering YLL and YLD values, or compute each component from raw epidemiological inputs.

How it works

Choose whether to enter YLL and YLD directly or compute them from component inputs.
For YLL: enter the number of deaths and the standard life expectancy at age of death; multiply to get YLL.
For YLD: enter incidence (new cases), average disability weight (0–1), and average disease duration in years; multiply to get YLD.
DALY = YLL + YLD — the sum represents total healthy-life-years lost in the population.
Review the breakdown table showing each component and its share of total DALYs.
Use the per-population rate (DALYs per 100,000) for cross-population comparisons.

Use cases

Global Burden of Disease (GBD) study calculations for a specific condition.
Compare health loss from mortality vs. disability for policy prioritization.
Academic epidemiology assignments and public health research.
Health-economic analyses that require a single burden-of-disease metric.
Estimating DALYs averted by an intervention for cost-effectiveness studies.
Teaching burden-of-disease concepts in public health courses.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu