How Whoop calculates recovery, and how to get a recovery score without Whoop

Whoop calculates its recovery score each morning from four signals recorded while you sleep: heart rate variability (HRV), resting heart rate (RHR), sleep performance and respiratory rate. Each signal is compared with your own baseline, and the result is a percentage from 0 to 100: green at 67% or higher, yellow at 34–66% and red at 33% or lower.

You can get a score built on the same idea without a Whoop band. Any device that records overnight HRV or resting heart rate plus sleep gives the raw inputs. The sections below explain the Whoop method in detail, then show the alternatives and their trade-offs.

How does Whoop calculate recovery?

Whoop Recovery is a daily percentage based on four physiological metrics: HRV, resting heart rate, sleep and respiratory rate. Whoop measures them during sleep, compares each with your own recent history and combines them into one score. Whoop publishes the inputs and color zones, but not the weights or the formula.

What Whoop says about each input on its own pages:

Input	What Whoop says it measures	Effect on Recovery
Heart rate variability	RMSSD, calculated during sleep	A major contributor. Higher than your normal tends to raise the score
Resting heart rate	Heart rate at rest during sleep	Lower than your normal tends to raise the score
Sleep performance	Sleep you got compared with the sleep you needed	More of your sleep need met tends to raise the score
Respiratory rate	Breaths per minute during sleep	Usually stable. Whoop says a large shift is likely meaningful and possibly a sign of sickness

Caption: Whoop "How does WHOOP Recovery work" and Whoop HRV training article, as of October 2026.

The design follows established sports science. Plews et al. (2013) found that one-week averages of HRV and resting heart rate tracked changes in running performance much better than single-day values. That is why a baseline, not a fixed population target, sits at the center of Whoop's score and of most others. Our recovery score guide explains the baseline idea in depth.

What do the green, yellow and red zones mean?

Whoop groups its 0 to 100% scale into three colors. Green (67–99%) means Whoop considers you well recovered. Yellow (34–66%) means your body is maintaining and can handle moderate strain. Red (1–33%) means rest is likely what your body needs. The colors are guidance for training, not a medical judgment.

Zone	Recovery %	Whoop's description	Practical reading
Green	67–99	Well recovered, primed to perform	A planned hard session fits
Yellow	34–66	Maintaining, ready for moderate strain	Train, but consider less intensity or volume
Red	1–33	Rest is likely what your body needs	Easy movement or rest, check sleep and stress

Caption: zones from Whoop's Recovery page. The practical column is our general reading, not Whoop guidance.

Whoop pairs Recovery with a separate Strain score (0 to 21) that tracks how much load you took on during the day. The two work as a pair: recovery suggests what you can handle, strain shows what you did. See what is strain for how strain scores work.

How does Whoop measure HRV?

Whoop reports HRV as RMSSD (root mean square of successive differences between heartbeats), calculated automatically during your deepest sleep each night. RMSSD reflects short-term, beat-to-beat changes and is the main time-domain measure used to estimate parasympathetic activity, according to a 2017 review by Shaffer and Ginsberg.

Measuring during sleep removes most daytime noise from posture, movement, caffeine and talking. That makes nightly values more consistent from day to day, which matters for a score that depends on small changes against your baseline.

Why Whoop HRV and Apple Watch HRV do not match

Apple Watch stores overnight HRV in Apple Health as SDNN (standard deviation of normal-to-normal intervals), according to Apple's HealthKit documentation. iOS 27 adds an RMSSD type. SDNN and RMSSD are different calculations, and the same heartbeat recording gives different numbers for each. A person can see 45 ms on one device and 70 ms on another on the same night without anything being wrong. Compare each device only with itself. Our guide to RMSSD vs SDNN explains why.

What does Whoop cost?

As of October 2026, Whoop sells three annual memberships on its own site, and the band is included with each. One costs $199 a year, Peak $239 a year and Life $359 a year. All three include Recovery. Higher tiers add health features such as Health Monitor, Stress Monitor and, on Life, blood pressure insights and ECG.

Membership	Annual price (US)	What Whoop says the tier adds
One	$199	Sleep, strain and recovery, coaching, VO2 max and heart rate zones
Peak	$239	Health Monitor, Stress Monitor, Healthspan
Life	$359	Blood pressure insights, Heart Screener with ECG (requires Whoop MG)

Caption: Whoop membership page, as of October 2026. Prices and features can change. Check Whoop's site before buying.

Can you get a Whoop-style recovery score without Whoop?

Yes. A Whoop-style score needs three things: overnight HRV or resting heart rate, sleep data and a baseline built from your own history. Several devices and apps provide that. The main differences are which inputs they read, which hardware they need and whether the score shows what moved it.

Option	What you need	Inputs	Notes
Apple Readiness	Apple Watch Series 12 or Ultra 4	Activity, Training Load, vitals, sleep score	0–10 scale, needs 7 nights of overnight vitals
Oura Readiness	Oura ring	Sleep, activity balance, resting heart rate, HRV balance, temperature, recovery index	0–100 scale
Garmin Training Readiness	Supported Garmin watches	Sleep score, recovery time, HRV status, acute load, sleep and stress history	1–100 scale
App that reads Apple Health	iPhone, plus any device that writes to Apple Health	HRV, resting heart rate, sleep from Apple Health	Quality depends on what your device records
Morning camera HRV	iPhone only	RMSSD from a 20–30 second finger reading	No overnight data, so needs a consistent morning routine

Caption: each company's own documentation, as of October 2026.

For Apple Watch owners specifically, see Apple Watch recovery score. For a broader list of subscription-free options, see Whoop alternatives.

How can you check your recovery by hand?

You can run a simple version of the Whoop method yourself. Take the same reading at the same time each morning, keep a 7-day average, and compare today with that average. A morning resting heart rate several beats above your average, together with lower HRV and short sleep, points the same direction as a red Whoop day.

Step	What to do	Why
1	Measure HRV or resting heart rate right after waking, before coffee, same position each day	Removes posture and caffeine effects
2	Record hours slept	Sleep is one of the four Whoop inputs
3	Keep a 7-day rolling average for each number	Weekly averages track training adaptation better than single days (Plews et al., 2013)
4	Compare today with the average	The change matters, not the absolute value
5	Adjust training when 2 or more signals move the wrong way	One signal alone is often noise

If your numbers stay well outside your normal range for several days and you feel unwell, rest and see a doctor. Neither Whoop nor any other recovery score can tell you the cause.

How Svanu gives you a recovery score without Whoop

Svanu reads Apple Health and compares this morning's HRV and resting heart rate with your own recent baseline, plus last night's sleep. It works with Apple Watch and with other devices that sync to Apple Health. The baseline is provisional after 3 nights and full at 7, and every score shows the inputs that moved it.

Details that matter if you are coming from Whoop:

• No band required: on iPhone alone, a 20 to 30 second camera reading measures RMSSD. Camera readings are compared only with camera readings, never with a watch's overnight SDNN.
• Fallbacks: if your device does not write HRV, recovery uses resting heart rate and sleep. With neither, it gives an estimate from sleep and how you feel, labeled as an estimate.
• Strain to match: a separate 0 to 100 strain score and a daily target strain band based on today's recovery and your own recent strain history.
• Price and privacy: the core app is free. Pro is $2.99 a month or $19.99 a year with a 7-day free trial. All scores are computed on the iPhone, with no sign-up.

See how the scores fit together on the Svanu home page.