Sleep Cycles & Sleep Debt Calculator

Calculate optimal bedtimes based on 90-minute sleep cycles and track weekly sleep debt from Apple Health data.

Frequently Asked Questions

How long is a natural human sleep cycle?

An average sleep cycle lasts approximately 90 minutes, cycling through Light (Core), Deep, and REM sleep stages.

Watch Faces

Mini Games — Four games on your watch — Bricks, Snake, 2048 and Tic Tac Toe. Play in the app, then read the frozen frame of your last game right on the dial, next to battery, weather, steps and calories. Inspired by 2048 by Gabriele Cirulli (MIT).
Pocket Pals — A virtual pet you raise — it grows through life stages, shows its mood, and lives in a little world that blooms with good care. The four rings are your real data: battery, weather, steps and calories.
Bunker Dashboard — Retro phosphor terminal with weather, battery charge, and vital stats.
Weather Dashboard — Current weather and conditions, daily low (↓) and high (↑) temperature, wind speed, and battery. Powered by Apple Weather.
Weather Simple — Current weather icon and temperature at a glance, daily low (↓) and high (↑) temperature, wind speed, and battery. Powered by Apple Weather.
Retro Dashboard — Casio-style 7-segment LCD with battery, exercise minutes, distance, heart rate, steps, weather, and humidity.
Outdoor Companion — Temperature, wind speed, steps, distance and calories — everything for your outdoor adventures. Battery level included.
Blueprint Dashboard — Industrial blueprint frames with date, weather, steps, calories, flights climbed and battery.
Weather Condition — Current weather condition with temperature and localized date. Battery level included.
UV & Sun Tracker — UV index with sun arc, hourly UV forecast, sunrise time, sunset countdown and temperature.
Rain Forecast — Minute-by-minute precipitation forecast with adaptive status, precipitation chance, humidity, temperature and wind.
Fitness Dashboard — Track your activity with a dynamic robot companion. Battery, temperature, steps, calories, exercise minutes, and stand hours.
Active Dashboard — Heart rate, steps, distance and weather at a glance.
Step Counter — Steps as the main focus with progress toward 10,000 goal. Distance, calories and battery at a glance.
Moon Phase — Track the lunar cycle with current phase, percentage, and days until the next full moon.
Heart Rate Zones — Track your heart rate zones with daily chart, current heart rate, and key metrics.
Heart Rate Live — Live heart rate with ECG visualizer and daily activity metrics.
Doodle Dashboard — Playful hand-drawn marker face with date, weekday, battery, steps, calories, heart rate and temperature in colorful doodles
Racer Dashboard — Automotive instrument cluster with twin dials for steps and heart rate, plus gauges for humidity, battery and temperature
Digital Cluster — Glowing twin-dial cluster with battery, steps, heart rate, distance, humidity and temperature gauges
NEON GAUGE — Big glowing numbers over gradient arc gauges
Vitals Weather — Weather, steps, calories and heart rate at a glance on a bold filled dashboard.
Vitals Activity — Steps, calories, distance and heart rate — your full activity picture.
Vitals Heart Rate — Live heart rate front and center with calories, steps and stand hours.
Vitals Rings — Move, exercise and stand goals with steps, calories and distance.
Vitals Date — A large date with daily activity — steps, calories and heart rate.
Vitals Calories — Active energy and activity — calories, steps, distance and heart rate.
Vitals Distance — Distance, steps, calories and heart rate for every workout.
Vitals Moon — Moon phase, sunrise and sunset with steps and battery.
Vitals UV — UV index, sunrise and sunset with temperature, humidity and steps.

Curated Packs

The Weather Pack — Five ways to read the sky — from hourly UV to minute-by-minute rain forecasts.
The Outdoor Pack — Built for the trail, the summit, and the long way home.
The Fitness Pack — Activity rings, heart rate zones and step counters — every metric within a glance.

Apple Watch Guides & Articles