AHI Calculator | Apnea-Hypopnea Index

Written by Great Medico

Updated September 24, 2026 •2 min read

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Sleep problems are rarely captured by one number, but a focused score can still organize useful information. AHI Calculator | Apnea-Hypopnea Index summarizes exactly the inputs shown in the tool.

What this calculator does

The apnea-hypopnea index, or AHI, summarizes how often apneas and hypopneas occur per hour of sleep. This calculator turns event counts and sleep time into the familiar events-per-hour measure. Sleep questionnaires and indices are screening or descriptive tools; symptoms, sleep opportunity, and formal sleep testing may add information that the score cannot capture.

How to use it

Enter or select Apneas, Hypopneas, and Sleep time. Use the units offered by the calculator and keep measurements consistent when you plan to compare results over time.

How the calculation works

AHI = (number of apneas + number of hypopneas) ÷ total sleep time in hours. The calculator then applies its stored adult severity bands: below 5, 5 to under 15, 15 to under 30, and 30 or more events per hour.

Example

For the sample values prefilled in this calculator, the primary result is 5 events/hour (Mild range). This example is there to show how the inputs flow through the implemented equation; replace the sample values with your own measurements before using the result.

How to interpret the result

The result can be read as the average frequency of scored breathing events during the sleep period entered. Severity categories are useful context, but symptoms, oxygen desaturation, sleep stage, body position, and comorbidities also matter.

Limitations and notes

AHI depends on how apneas, hypopneas, and actual sleep time are measured and scored. Home studies and polysomnography can produce different denominators or scoring detail. This calculator does not diagnose obstructive versus central sleep apnea and cannot replace a formal sleep-study interpretation. If the result conflicts with strong symptoms—such as witnessed breathing pauses, dangerous daytime sleepiness, or persistent insomnia—symptoms should not be dismissed because of a reassuring score. Screening tools are designed to support, not replace, evaluation.