THE NUMORIX GUIDE
How to use the TDEE Calculator
Last reviewed September 14, 2026
What this calculator does
The engine converts imperial weight and height to kilograms and centimeters, then applies Mifflin-St Jeor: for male, BMR = 10w + 6.
Formula and method
The engine converts imperial weight and height to kilograms and centimeters, then applies Mifflin-St Jeor: for male, BMR = 10w + 6.25h - 5a + 5; for female, BMR = 10w + 6.25h - 5a - 161. It multiplies BMR by 1.2, 1.375, 1.55, 1.725, and 1.9 for sedentary, light, moderate, active, and very active estimates. The returned tdee field is the moderate 1.55 result.
Variables and inputs
Enter weight in lb or kg, height in inches or cm, age in years, and the male or female formula choice. Outputs are BMR and activity-adjusted calories per day. The imperial conversion uses 0.453592 kg/lb and 2.54 cm/in.
Worked example
For a 170 lb, 70 inch, 30-year-old male, converted values are 77.11064 kg and 177.8 cm. BMR = 10(77.11064) + 6.25(177.8) - 5(30) + 5 = 1,737 kcal/day. The activity estimates are about 2,085 sedentary, 2,389 light, 2,693 moderate, 2,997 active, and 3,301 very active kcal/day.
How to interpret the result
BMR is the equation's resting-energy estimate; TDEE is a scenario after multiplying it by an activity factor. The page's headline BMR is not the number to use as a maintenance target for an active person, and the displayed moderate value is only one of five activity scenarios.
Common mistakes to avoid
Use kilograms and centimeters in metric mode and pounds and inches in imperial mode. Select the formula profile that matches the available reference rather than treating it as a biological diagnosis. Do not add exercise calories again after choosing an activity multiplier unless you intentionally model a separate scenario.
Assumptions and limitations
Mifflin-St Jeor is a population equation and the activity multipliers are coarse. The model does not account for body composition, illness, pregnancy, breastfeeding, adaptive changes, exercise duration, food thermic effect beyond the multiplier, or day-to-day variation. Adjusting food intake should be based on trends and appropriate professional guidance, not one calculated number.