Head to head
Sixteen and WHOOP answer the same morning question, how recovered am I, in two different ways: WHOOP sells a strap with a yearly membership, Sixteen is an app for the wearable you already own, including a WHOOP strap, for one payment.
Short version
WHOOP is a strap plus a membership. Sixteen is software for the wearable you already own, including a WHOOP strap. If you want the screenless band and are happy paying yearly, WHOOP is a polished choice. If you own an Apple Watch or a WHOOP strap and want recovery, food, lifting and screen time in one app for one payment, Sixteen is built for you.
| Sixteen | WHOOP | |
|---|---|---|
| Recovery score |
Capped by sleep, load, journal | |
| HRV |
rMSSD, baseline band | |
| Sleep score |
Need, consistency, efficiency, stress |
Performance vs need |
| Respiratory rate | From Apple Watch Not from a strap over Bluetooth | |
| Skin temperature, SpO2 |
Strap sensors | |
| Strain |
HR zones plus lifted load |
0 to 21 |
| Strength log with sets and reps |
Strength Trainer estimates load | |
| Food log with database |
Journal tags | |
| Screen time control | ||
| Works with Apple Watch | ||
| Works with WHOOP strap |
Direct Bluetooth, no membership | |
| Screenless wearable included | ||
| Price | $99 once or $19.99 a month | $199 to $359 a year |
| Five year cost | $99 | $995 to $1,795 |
Competitor details from public product pages, checked September 2026. No accuracy claims are made against either product. Corrections welcome at keshav@sixteen.life.
Both build a daily recovery percentage from overnight HRV, resting heart rate and sleep against your own baseline. WHOOP adds respiratory rate and skin temperature from its strap. Sixteen adds respiratory rate from Apple Watch, caps the score by sleep, load and journal so nothing is counted twice, and publishes the method.
WHOOP scores sleep performance against a need and offers a sleep planner. Sixteen scores hours against need, consistency, efficiency and sleep stress, and then locks distracting apps for the whole night on your schedule.
WHOOP's strain is a 0 to 21 cardio load with a Strength Trainer that estimates muscular load. Sixteen scores time in heart rate zones plus muscular load from sets you actually log, and gives you a rep by rep strength log with progression.
WHOOP's journal tags behaviours like alcohol and late meals. Sixteen has a journal and a food log with a searchable database, photo logging and macro targets.
WHOOP has none. Sixteen locks the apps you choose, pays out minutes for movement and sleep, opens a short window for three breaths, and locks everything at bedtime.
WHOOP: strap included in a $199, $239 or $359 yearly membership; the strap stops when you stop paying. Sixteen: no hardware, $99 once or $19.99 a month, works with Apple Watch and reads a WHOOP strap directly over Bluetooth with no membership.
Best for
Best for Apple Watch owners
WHOOP does not read a watch. Sixteen does.
Best screenless wearable
The strap is the reason people love WHOOP.
Best for lifting and food
Sets, reps and a food database in the same app as recovery.
Best without a membership
One payment, and a lapsed WHOOP strap keeps working.
Best for behaviour change
The only one of the two that can lock your apps.
SixteenSixteen is $99 once for lifetime access, or $19.99 a month. Connect the wearable you already own. No hardware to buy, no membership that expires.
iPhone (iOS 17 or later). Prices in USD.