A Quality-Adjusted Life Year (QALY) is a measure of disease burden that accounts for both the quantity and quality of life. One QALY = one year in perfect health. It is the standard outcome metric in health technology assessments worldwide.

What is a health utility score?

A utility score is a number between 0 (death) and 1 (perfect health) representing the desirability of a health state. Scores are usually derived from instruments such as EQ-5D, SF-6D, or HUI. Negative values are possible for states considered worse than death.

What is ICER and what threshold is acceptable?

The Incremental Cost-Effectiveness Ratio (ICER) = incremental cost ÷ incremental QALYs. Common thresholds: NICE (UK) uses £20,000–£30,000 per QALY; the US often references $50,000–$150,000 per QALY; WHO suggests 1–3× GDP per capita per QALY.

Can utility scores be negative?

Yes. Some health states (e.g. severe chronic pain, ventilator dependence) are valued worse than death by some people, yielding utility scores below 0. This calculator accepts negative utility values.

How is QALY different from life years gained?

Life years gained counts only time; QALYs weight that time by health-related quality of life. A treatment that extends life by 2 years at 0.5 utility gives 1 QALY — equivalent to 1 year in perfect health.

QALY Calculator

Enter life years and a health utility score to compute QALYs and ICER for cost-effectiveness analysis.

Intervention

Life Years (Intervention)

Health Utility Score (0 = death, 1 = perfect health)

Comparator (optional)

Enable

Life Years (comparator)

Health Utility Score (comparator)

Incremental Cost ($) (intervention − comparator)

Enter values and click Calculate QALYs

Summary

A QALY (Quality-Adjusted Life Year) combines length of life with quality of life into a single number. One QALY equals one year in perfect health (utility = 1.0); a year at half quality counts as 0.5 QALYs. This calculator computes QALYs gained from an intervention and, optionally, the Incremental Cost-Effectiveness Ratio (ICER) against a comparator.

How it works

Enter the life years under the intervention in the "Life Years (Intervention)" field.
Enter the health utility score (0 = death, 1 = perfect health) for the health state during those years.
QALYs = Life Years × Utility Score — the result appears instantly.
To compare two options, fill in the "Comparator" section with that option's life years and utility.
Enter the incremental cost difference to compute the ICER (cost per QALY gained).
Compare the ICER against common willingness-to-pay thresholds (e.g. $50,000 or $100,000 per QALY).

Use cases

Evaluate a new drug's cost-effectiveness versus standard of care.
Compare two surgical procedures on a quality-of-life-adjusted basis.
Estimate health gain from a public health intervention.
Prepare a health technology assessment (HTA) submission.
Teach health economics concepts to students and clinicians.
Quickly benchmark an ICER against NICE or WHO thresholds.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu