How to Use AHI Calculator
Use AHI Calculator when you have a sleep study summary listing total sleep time, apnea events, and hypopnea events. Enter sleep time in hours, then enter each event count separately.
The calculator returns events per hour and a severity band. If your report gives sleep time in minutes, divide by 60 first; for example, 390 minutes equals 6.5 hours.
Formula & Theory - AHI Calculator
The core calculation is:
AHI = (apnea events + hypopnea events) / total sleep hoursAHI standardizes breathing event counts by actual sleep duration. This matters because 40 events over 8 hours and 40 events over 4 hours represent very different event rates.
Common interpretation thresholds are under 5 events/hour as normal, 5 to 14.9 as mild, 15 to 29.9 as moderate, and 30 or more as severe. Clinical interpretation may also consider oxygen desaturation, symptoms, and comorbidities.
Use Cases for AHI Calculator
Use it to double-check a sleep report, compare nights in home sleep testing, or explain why short sleep duration can raise the event-per-hour index.
It is useful for patient education before discussing treatment options such as positional therapy, CPAP, oral appliances, weight management, or further diagnostic review.