Sleep & HRV recovery
Reads sleep duration, consistency, and heart rate variability from Apple Health. Works with Apple Watch, Oura, Ultrahuman, Whoop, Garmin, and most third-party wearables.
Know how hard
you can work
today.
Capacity Gauge reads your sleep, HRV, and calendar on-device and delivers one daily score — so you start each morning with a clear, honest read on your readiness. No guesswork. No cloud.
Health data never leaves your device. No account required.
Today
Thursday
78
Good
Mar 26, 2026
You got slightly less sleep than usual last night.
Sleep 12% below your 14-day average
4.5h of meetings on the calendar
HRV within normal range
Protect one deep-work block
With 4h of meetings, carve out 90 min before lunch for focused work while energy is higher.
Wind down 30 min earlier tonight
Last night was short. An earlier cutoff helps rebuild sleep pressure for tomorrow.
Private by design — everything stays on your iPhone
Sleep data, HRV, calendar events, and your readiness score are processed entirely on-device using Apple Health and EventKit. Nothing is sent to a server. No account, no subscription required to use the core features.
Calendar load analysis
Counts meeting hours, context switches, and back-to-back blocks for the day ahead. Heavy days reduce your score before you've even started.
One honest score
A single 0–100 readiness number with a plain-English status. No streaks to maintain, no guilt. Just a clear signal for how to approach today.
Anomaly detection
Detects early wake, short sleep, and fragmented nights relative to your personal 14-day baseline — not generic population averages.
Actionable suggestions
Each morning you get 1–3 concrete suggestions tailored to your score, sleep anomalies, and the day’s calendar load. Not generic advice.
Adapts to your work pattern
Tell it whether you do deep focus work, mixed work, or mostly collaboration — and the calendar penalties adjust to what actually matters for your role.