Enter how much sleep you need per night and how much you actually got over the last 7 nights.
Sleep debt = (needed sleep − actual sleep) added up across the nights you enter. It's a simple, direct way to see your cumulative shortfall, based entirely on the numbers you provide.
Individual sleep needs vary — 7–9 hours is a commonly cited range for adults, but the number you enter should reflect what actually works for you. This is a simple tracking tool, not medical advice.