Skip to content

My Cart

Your cart is empty

Continue shopping

Armband Size Guide

Upper arm circumference

How to Measure

  1. 1Wrap a flexible tape measure around your upper arm
  2. 2Measure at the fullest part (mid-bicep)
  3. 3Note in inches or centimeters

Size chart

Size Inches cm
Standard Armband 8.5″ – 15.5″ 21.5 – 39 cm
Extra-Long Armband 12.5″ – 18.5″ 31.5 – 47 cm
Both armbands fit most body types.
Additional bra extenders can be purchased at any store if larger sizing is required.

Fertility Q&A

Can I chart with a copper IUD?

Birth control

Can I chart with a copper IUD?

Yes! You can chart your cycles with a copper IUD if you want. Some find charting with a copper IUD to be slightly more difficult than without it, but it is a very valid option.

Read more
Birth control

I just came off hormonal birth control - how long do I have to wait before I can trust fertility awareness for family planning?

This is highly dependent on the person. If you choose to self-teach, most methods suggest waiting at least 3 full cycles before starting to trust fertility awareness on its own for family planning....

Read more
Birth control

Can I chart while on hormonal birth control?

You can chart your symptoms while on hormonal birth control, but most hormonal birth control suppresses ovulation, so you won’t have “complete” charts, and they may be confusing to understand. Char...

Read more
Birth control

I just came off hormonal birth control - how long should I wait to start charting?

You can start charting right away after coming off hormonal birth control. In fact, you can even start charting symptoms before coming off hormonal birth control!

Read more
Birth control

How effective is fertility awareness in family planning?

Fertility awareness can be up to 99.6% effective for family planning. The study that produced this result was based on the Sensiplan (a symptothermal, double-check, method), learned under a qualifi...

Read more
Birth control

Can I use barriers while using fertility awareness?

This is completely up to you! When you use fertility awareness, the ball is in your court. You get to decide what is or isn’t too much risk. While abstinence provides the most security over your fa...

Read more