Sleep Tools
Sleep Cycle Calculator
Free sleep cycle calculator that finds the best bedtime or wake-up time based on 90-minute sleep cycles.
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5 free tools · no signup
Sleep cycle and nap calculators, brown-noise generator, ambient sound mixer, and caffeine cutoff timing — all browser-based, no signup. Every tool runs in your browser, requires no account, and stays free forever.
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5 tools available — free, no signup, instant.
Sleep Tools
Free sleep cycle calculator that finds the best bedtime or wake-up time based on 90-minute sleep cycles.
Sleep Tools
Find the right nap length — power, recovery or full cycle — based on time available and your goal.
Sleep Tools
When to stop drinking caffeine before bed, based on caffeine's 5-hour half-life and your bedtime.
Sleep Tools
Free brown noise generated live in your browser — sleep, focus and tinnitus relief, with a sleep timer.
Sleep Tools
Mix brown, pink, white noise plus rain and ocean ambience into your own sleep or focus soundscape.
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