Your sleep debt is
What is sleep debt, and how much do you have?
Sleep debt is the running total of sleep you’ve missed against what your body needs. If you need 8 hours but average 6, you build up 2 hours of debt every night — and it adds up fast across a week. Enter your typical nightly sleep, how many nights to count, and your target, and this calculator shows the total you’re carrying, so you know how much catch-up rest to aim for.
This is a simple estimate to raise awareness, not medical advice. You can’t fully “repay” heavy debt in one lie-in — steady, consistent nights work best. Ongoing tiredness despite enough hours can signal a sleep disorder; see a doctor if that’s you.
Frequently Asked Questions
How much sleep do I actually need?
Most adults need 7–9 hours a night, with 8 a common target. Teens need more. Set your own target above based on when you feel genuinely rested.
Can I catch up on lost sleep at the weekend?
Partly. A lie-in helps a little, but big “sleep binges” throw off your body clock. Recovering gradually — an extra 30–60 minutes a night — works better than one long weekend sleep.
What are the effects of sleep debt?
Even a few hours of accumulated debt can dent focus, mood, appetite control and immunity. Chronic debt is linked to more serious long-term health risks.
How do I pay it down?
Prioritise a consistent bedtime, wind down without screens, keep the room cool and dark, and go to bed a little earlier until you feel caught up.