nowfound

Life & fun · May 30, 2013

Sleep Debt Calculator

Free sleep tools: 34 instant calculators covering sleep debt, cycles, caffeine, naps, and jet lag — all free, no signup required.

Sleep Debt Calculator launched on May 30, 2013 with 26 votes, #88 of 587 launches that month and more than 75% of that year's launches. The site was still online in September 2026, 13 years on.

Visit sleepdebtcalc.com ↗Sleep Debt Calculator alternativestop 15% of May 2013

In plain words

Sleep Debt Calculator is a free online tool with 34 calculators designed to help users understand their sleep patterns. It tracks sleep debt by comparing actual sleep to target sleep over seven nights, showing shortfall, surplus, and net balance separately, plus offering a recovery plan. The suite also includes calculators for sleep cycles, caffeine effects, naps, and jet lag. No signup is required to use any of the tools.

written from the facts on this page · September 2026

From the sources

Free sleep debt calculator. Enter your last 7 nights and instantly see how much sleep you owe — plus a recovery plan and 13 more sleep tools.

34 free calculators for understanding and optimizing your sleep — start with your Sleep Debt Calculator below, then explore cycles, caffeine, naps, and jet lag. Shortfall is the sum of (target minus actual sleep) for every night you slept less than your target. Surplus is the sum of (actual sleep minus target) for every night you slept more. Net balance is surplus minus shortfall. We track these separately rather than letting one good night silently cancel out a bad one. The estimated recovery window is a rough, transparent estimate, not a clinical prediction. There is no validated formula for exactly how long it takes an individual to recover from a given sleep shortfall; the range shown…from sleepdebtcalc.com

Does a similar job

all alternatives →
  • Free Sleep Calculator Tool By ShutEye2024 · shuteye.ai · ▲5

    Sleep Tracking App to Monitor Your Sleep Cycle

  • Sleep Disorder Calculator2024 · sleepalora.com · ▲8

    User-friendly online calculator for an initial screening

  • Free Sleep Calculator2025 · sleepcalculators.org · ▲6

    Free sleep calculator and sleep cycle calculator to find your optimal bedtime and wake-up time. Calculate your REM sleep cycles for better rest and energy

  • IO CalculatorsJul 2026 · io-sleep-calculator.blogspot.com · ▲2

    Free, responsive tool to calculate your perfect sleep cycle.

  • SleepCalculators.net2025 · sleepcalculators.net · ▲6

    Free sleep tools to help you wake up refreshed

  • Nod: Sleep Debt TrackerAug 2026 · play.google.com · ▲1

    Track sleep debt and optimize daily recovery offline.

More life & fun this month

the category →

Source: Show HN post ↗

Launched alongside, May 2013

the whole month →