Getting Started with FAM: What kind of thermometer do I need?

To see my most up to date recommendations, check out The Best Basal Body Thermometers for 2023

The one thing you need to know

When looking for a thermometer to purchase, you want to look for a basal body thermometer. You shouldn’t compromise on this. Basal body thermometers, or BBTs for short, read to the 100ths (98.68) rather than 10ths (98.6). This provides the highest accuracy. To learn more about how to get the most out of your basal body temperatures, read my Basal Body Temperature Troubleshooting Guide.

Features to consider:

• Back light – ideal if you’re taking your temperature in the early morning before the sun comes up
• Measurement time – most methods recommend a minimum of 3 minutes, the longer the thermometer stays in your mouth, the more accurate the temperature will be. If you choose a thermometer with a shorter temp time and find that you have unstable temperatures, consider leaving the thermometer in your mouth for 2 minutes before turning it on.
• Memory – Some people find they get more stable temperatures by waking early in the morning (5-6am) to take their temperature and then going back to sleep until their normal wake time. Having a thermometer with a memory allows you to fall back to sleep immediately and enter your temperature when you finally wake for the day.
• Alarm – Taking your temperature at the same time every day is important for accuracy and consistency. If you try to keep your phone away from your bed, then a thermometer with a built in alarm could be ideal.

Thermometers to consider

Up&Up Target Brand BBT

This one is really popular because it’s so affordable and may be found in your local store.

Pros:

• It’s affordable (around $8)

Cons:

• 1 minute temp time
• Possibly only in F
• Possibly no memory

Femometer Vinca Lite

This is my favorite cheapie thermometer because it can temp for 3-5 minutes while most thermometers only temp 30-60 seconds.

Pros:

• It’s affordable (around $10)
• C/F switchable
• 3-5 minute temp time
• 1 temp memory

Cons:

• Doesn’t have a back light

*UPDATE: It appears that this thermometer is now being sold as an upgraded model and reads for as little as 30 seconds and as much as 5 minutes. I would recommend the Vinca II over this model due to the longer temping time.

iProven 113i

ONETWOTHREE BBT

This model has been known by several names, including iSnow-Med. This is another really popular thermometer, but the probe is a little on the thick side. Ideal for vaginal temping for that reason.

Pros:

• Decently priced (around $20),
• C/F switchable
• Back light
• 2-3 minute temp time
• 60 day memory with date and time
• Built in alarm
• Thicker probe – ideal for vaginal temping

Cons:

• Some users have said the thicker probe is uncomfortable for oral temping,
• It’s also a bit larger than most BBTs in general

*UPDATE: Since Covid, the popular iSnow-Med version appears to have been discontinued.

Femometer Vinca II

This is my personal favorite, you can read my full review here. This thermometer connects by bluetooth to the Femometer app where you can customize the thermometer settings and sync your temps to the Femometer chart (not an app I recommend for charting). It has the temperature readout directly on the thermometer (whereas Vinca I does not) so after you customize your settings you don’t really need to use the app.

Tempdrop

A wearable thermometer that goes on your upper arm near your armpit or in your sleep bra all night. It has a proprietary algorithm that may help you get more stable temperatures. Ideal for people who have an irregular wake schedule, shift work, or are postpartum. You can read my full review of Tempdrop here.

Pros:

• Helps many people chart who wouldn’t be able to with a standard BBT (scenario examples above)
• 99% of users surveyed said they were happy with their experience,
• Temps all night long,
• A large Facebook community,
• Helpful customer service

Cons:

• May be uncomfortable for some people when worn on the arm (especially for larger arms),
• Some people may experience delayed temperature shifts compared to oral temps,
• Frames break easily and while the company continues to replace them for free as they work out the manufacturing issues, it may cause an inconvenience if you don’t have a spare frame to use while you wait for the replacement (spare frames and bands can be purchased if desired)

Purchasing options: Basic package is currently on sale 20% off on Amazon or purchase one of three packages on their website ($159-249) and get $15 off using this link

Or Support Small Business

I also have a basic Digital Basal Body Thermometer available for sale. Due to the COVID-19 pandemic, thermometers have been hard to come by or are delayed in shipping. I wanted to be able to offer another option. They are ready to ship immediately (in the US only) and should arrive in 1-3 business days. Contact me to purchase.

If you have any questions or comments feel free to drop them in the comments below or send me a message!