The Beurer OT 30 Bluetooth Basal Temperature Ovulation Monitor is a digital basal thermometer built for natural cycle tracking and family planning. It measures your basal body temperature to two decimal places and pairs with the free "Ovy" cycle-tracking app, so you can follow the small temperature shifts across your cycle that natural family planning (NFP) methods rely on to identify likely fertile and non-fertile days.
If you're charting your cycle to understand your fertile window — whether you're trying to conceive or simply want to get to know your rhythm — this is a purpose-made basal thermometer rather than an ordinary fever thermometer. It reads in finer increments, records your daily measurements, and sends them straight to your phone over Bluetooth so you can see the pattern build up over time.
How it works
- Basal temperature charting: Basal body temperature is measured at rest and read to two decimal places, so you can track the subtle day-to-day changes that NFP charting is based on. It's worth knowing that basal temperature is a retrospective signal — a sustained shift is consistent with ovulation having occurred, rather than a prediction of it.
- App-connected tracking: Measurements transfer over Bluetooth 4.0 to the "Ovy" app (iOS 10.0 and Android 5.0), which keeps your readings together and shows your cycle pattern in one place.
- Guided measuring time: Each reading takes approximately 3 minutes, in line with the measuring time recommended for NFP, using contact-measurement technology for a stable result.
- Measurement accuracy: Accurate to ±0.05°C between 35.00°C and 38.00°C (at an ambient temperature of 18.00°C–28.00°C) and ±0.1°C across the rest of its 32.00°C–42.99°C range.
- Data-transfer feedback: An illuminated LED ring shows you when data is transferring, so you know the reading has been captured.
Practical, everyday details
The OT 30 is designed to fit into a daily routine. It has a flexible measuring tip and is suitable for both oral and vaginal measurements, and you can switch the reading between °C and °F. It's waterproof and can be disinfected, and it stores up to 30 measurements on the device itself. A signal tone lets you know when a measurement is finished (and can be switched on or off), while automatic switch-off and a battery-change indicator help you keep it ready to use. It comes with a protective cap for hygienic storage and runs on a 3V CR2032 button cell, which is included so you can start straight away. Beurer backs it with a 5-year limited warranty.
Best For
The Beurer OT 30 is a great option if you:
- Are following a natural family planning or cycle-tracking method and want a basal thermometer that reads to two decimal places
- Prefer to log your daily readings automatically in an app rather than charting by hand
- Want the flexibility of oral or vaginal measurement in one device
It may not be the right fit if you:
- Are looking for a urine-based ovulation-prediction test that detects an LH surge
- Need a general-purpose fever thermometer for the whole family
Disclaimer
The OT 30 is a medical device intended for basal temperature measurement and cycle tracking. It does not diagnose fertility, confirm that ovulation has taken place, or work as a method of contraception. For interpreting your readings or any concerns about your cycle or conception, speak to your healthcare professional, and follow the included instructions for use.
Care & Maintenance
Display to 2 decimal places
Measurement time approx. 3 minutes (recommended per NFP)
Contact-measurement technology
Suitable for oral & vaginal measurements
Illuminated LED ring for displaying data transfer
Flexible measuring tip
30 memory spaces
Automatic switch-off
Signal tone at end of measurement (On/Off)
Indication of °C/°F
Battery changing indicator
Waterproof
Can be disinfected
Comes with protective cap
- 1x Basal thermometer
- 1x Protective cap
- 1x 3V button cell battery CR2032
- 1x Set of instructions for use