What it does
The quiz asks four questions and shows three numbers: your estimated BMR, a daily calorie target, and Coach Josh’s protein range. You can see them without entering an email.
The BMR calculator page does the resting part on its own: your BMR plus daily maintenance calories for the activity level you pick.
The formula it uses
Both use the Mifflin-St Jeor equation, published in 1990. For women it is: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161. For men the last term is + 5 instead of − 161.
The quiz assumes a lightly active week, so maintenance is your BMR × 1.375. Your daily target is 500 calories below maintenance, and it never goes below 1,200 calories a day for a woman (1,500 for a man).
Protein first
The protein range is 0.9 to 1.0 grams per pound of your goal weight. That is Coach Josh’s coaching choice, not an official guideline: the adult RDA is 0.8 grams per kilogram of body weight a day. Starting each meal with protein makes the range easier to reach.
What it does not do
Get Your BMR is a starting estimate. It does not:
- Measure your metabolism. Only a lab test such as indirect calorimetry does that.
- Know your real activity. The quiz assumes a lightly active week.
- Diagnose anything or replace your doctor or dietitian.
- Account for pregnancy, medical conditions or medications.
How accurate is it?
It is as accurate as the formula behind it, and that formula is an estimate. Get Your BMR uses the Mifflin-St Jeor equation. A 2005 systematic review found it was the equation most likely to land within 10% of measured resting metabolism, but it can miss by more for any one person, and older adults were underrepresented in the studies. Use your number as a starting point, then adjust from two to three weeks of real results.
Who made it
Coach Josh (Joshua Saunders) of BodyByReason built Get Your BMR so women could see what their body burns at rest before guessing what to change. He also built the 3-Day Walk & Water Challenge, a walking and water challenge with a team, which runs in the APEX: Walk & Water app on iPhone and Android.
