Tempdrop vs Ava: Wearable Fertility Trackers Compared
Both let you track fertility while you sleep—but they work very differently.
Quick Comparison
- Tempdrop: Focused BBT tracker. Proven algorithm. Works with any cycle. More affordable.
- Ava: Multi-sensor bracelet. Tracks 5+ biomarkers. Best for regular cycles only.
- Winner: Tempdrop for most TTC'ers—better value, works for all cycle types.
Side-by-Side Comparison
| Feature | Tempdrop | Ava Bracelet |
|---|---|---|
| What It Tracks | Temperature only | Temp, pulse, HRV, breathing, sleep, perfusion |
| Wear Location | Upper arm (armband) | Wrist (bracelet) |
| Algorithm Focus | Precise BBT with noise filtering | Multi-sensor pattern recognition |
| Confirms Ovulation | ✓ Yes (temp shift) | ✗ Predicts only |
| Works for Irregular Cycles | ✓ Yes | ✗ Not recommended |
| Works with PCOS | ✓ Yes | ✗ Not recommended |
| App Integration | FF, Read Your Body, Kindara, own app | Ava app only |
| Price | $149-219 | $279-329 |
| Subscription Required | No | No (but optional) |
Tempdrop: In-Depth
What Is Tempdrop?
Tempdrop is a wearable BBT sensor that you wear on your upper arm overnight. Instead of waking up to take your temperature orally, Tempdrop continuously monitors your skin temperature while you sleep and uses an algorithm to calculate your true BBT.
How It Works
The sensor takes thousands of temperature readings throughout the night. Tempdrop's algorithm filters out "noise" (getting up to pee, room temperature changes, movement) to find your core BBT pattern. After 2 weeks of use, the algorithm is calibrated to your body.
The key advantage: no consistent wake time needed. Traditional BBT requires taking your temperature at the same time every morning before any movement. Tempdrop eliminates this requirement, making it perfect for shift workers, parents, or anyone with disrupted sleep.
App Integration
Tempdrop syncs with multiple fertility apps:
- Fertility Friend — automatic sync, gold standard for charting
- Read Your Body — privacy-focused, FAM-friendly
- Kindara — clean interface
- Tempdrop's own app — basic charting included
Pros
- ✓ No wake time requirement — works with any sleep schedule
- ✓ Confirms ovulation — shows BBT shift after O
- ✓ Works for all cycle types — irregular, PCOS, long cycles
- ✓ Syncs with multiple apps — use your preferred charting app
- ✓ No subscription — one-time purchase
- ✓ More affordable than Ava
- ✓ Active user community for support
Cons
- ✗ Only tracks temperature — no other biomarkers
- ✗ 2-week calibration period — first readings may be adjusted later
- ✗ Armband may shift in sleep (though rarely affects data)
- ✗ Learning curve for BBT charting newbies
Ava Bracelet: In-Depth
What Is Ava?
Ava is a multi-sensor wearable bracelet worn on the wrist overnight. Unlike Tempdrop's single focus on temperature, Ava tracks 5+ physiological parameters and uses machine learning to identify your fertile window.
What Ava Tracks
- Skin temperature
- Resting pulse rate
- Heart rate variability (HRV)
- Breathing rate
- Sleep quality
- Perfusion (blood flow to skin)
Ava's algorithm analyzes all these signals to predict your fertile window—claiming to identify 5+ fertile days per cycle.
The Catch: Regular Cycles Only
Ava's algorithm requires regular cycles between 24-35 days. It's explicitly not recommended for:
- Irregular cycles
- PCOS
- Cycles over 35 days
- Breastfeeding
- Menopausal transition
This significantly limits who can benefit from Ava.
Pros
- ✓ Multi-biomarker tracking — more data points
- ✓ Sleek bracelet design — more stylish than armband
- ✓ Pregnancy mode — continues tracking after conception
- ✓ Health insights beyond fertility
Cons
- ✗ Regular cycles only — doesn't work for irregular cycles or PCOS
- ✗ More expensive — $279+ vs Tempdrop's $149+
- ✗ Mixed accuracy reviews — some users report missed ovulation
- ✗ Only syncs with Ava app — can't use Fertility Friend
- ✗ Doesn't confirm ovulation — predicts only, no BBT shift
- ✗ Company has had financial troubles — longevity uncertain
Accuracy: Which Is Better?
Tempdrop Accuracy
Tempdrop excels at what it does: tracking BBT. The algorithm filters out noise and provides reliable temperature data that, when charted, shows a clear post-ovulation shift. Because BBT is a proven, well-understood fertility sign, Tempdrop's approach is evidence-based.
Tempdrop confirms ovulation by showing the temperature shift that occurs after the egg is released. This is valuable data.
Ava Accuracy
Ava's multi-sensor approach is more complex. While it can identify patterns associated with the fertile window, accuracy reviews are mixed. Some users report:
- Fertile window identified correctly
- Missed ovulation in some cycles
- Predictions that don't align with OPK results
Ava predicts but doesn't confirm ovulation. Without BBT shift data, you can't know for certain that ovulation occurred.
⚠️ Key Difference
Tempdrop confirms ovulation (shows the BBT shift after O).
Ava only predicts (estimates fertile window but can't prove O happened).
For TTC, confirmation matters—especially if you're concerned about anovulatory cycles.
Who Should Choose Which?
Choose Tempdrop If:
- You have irregular cycles or PCOS
- You're a shift worker or have disrupted sleep
- You have a baby/toddler waking you at night
- You want to confirm ovulation (BBT shift)
- You use or want to use Fertility Friend
- You prefer proven, straightforward BBT tracking
- You want to save money
Choose Ava If:
- You have very regular 24-35 day cycles
- You want multi-biomarker health tracking
- You prefer a bracelet over an armband
- You're interested in overall wellness data
- You don't need ovulation confirmation
- Budget isn't a concern
Other Options to Consider
Oura Ring: Primarily a sleep/health tracker, but some use it for fertility tracking. Not specifically designed for TTC but provides temperature and HRV data.
Regular oral BBT: If you have consistent wake times, a $25 smart BBT thermometer works just as well as Tempdrop for a fraction of the cost. Wearables are most valuable for inconsistent sleepers.
➡️ Related: Best BBT Thermometers
Frequently Asked Questions
I have PCOS—which should I choose?
Tempdrop. Ava explicitly states it's not for irregular cycles or PCOS. Tempdrop works regardless of cycle length or regularity because it's just tracking your actual temperature data.
Can I use Tempdrop with Fertility Friend?
Yes! Tempdrop syncs directly with Fertility Friend, which is the gold standard for BBT charting. This is one of Tempdrop's major advantages—Ava only works with its own app.
How long does the Tempdrop calibration take?
About 2 weeks. During this time, you'll get readings, but the algorithm may retroactively adjust earlier temps as it learns your body's patterns. After calibration, data is reliable from that point.
Is the Tempdrop armband comfortable?
Most users report it's comfortable once you get used to it. It can take a few nights to adjust. The band is soft fabric, and the sensor is small. Side sleepers occasionally need to adjust positioning.
Is Ava worth the extra money?
For most TTC purposes, no. Ava costs $100+ more than Tempdrop and has more limitations (regular cycles only, no ovulation confirmation). The multi-sensor data is interesting but hasn't proven more accurate for fertility tracking than temperature alone.
The Bottom Line
Tempdrop is our recommendation for most people trying to conceive. It's more affordable, works for all cycle types (including PCOS and irregular cycles), confirms ovulation with BBT shift, and syncs with the apps you actually want to use.
Ava is only worth considering if you have very regular cycles and specifically want multi-biomarker health tracking beyond fertility. For pure TTC purposes, Tempdrop delivers better value and more useful data.
Both eliminate the hassle of waking at the same time to temp, which is their main appeal. If that flexibility matters to you, either is better than traditional oral BBT—but Tempdrop is the smarter buy. 💚