Methodology and sources
Last reviewed 2026-10-22.
BMR
Mifflin-St Jeor equation (Mifflin et al., 1990): men, 10 x weight (kg) + 6.25 x height (cm) - 5 x age + 5. Women, the same with - 161 at the end.
TDEE and calories
- TDEE = BMR x activity factor: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 extra active. These are widely used multipliers, not measurements.
- Daily target = TDEE + goal in pounds a week x 3,500 / 7. The 3,500 calories per pound figure is a rough rule.
- A warning appears when the target is below 1,200 calories (women) or 1,500 (men).
- Adults only: ages 18 to 100.
Macros
Grams = calories x share / calories per gram, with 4 for carbs and protein and 9 for fat. The percentages must add up to 100.
BMI
BMI = weight (kg) / height (m) squared, or 703 x weight (lb) / height (in) squared. Categories for adults are from the CDC: under 18.5, 18.5 to 24.9, 25 to 29.9, and 30 or higher with obesity classes at 30, 35 and 40. The healthy range shown is the weight at a BMI of 18.5 to 24.9 for your height.
Protein
0.8 g per kg is the US recommended dietary allowance for adults. 1.4 to 2.0 g per kg is the range for physically active people from the International Society of Sports Nutrition position stand (Campbell et al., 2007).
Units and rounding
1 lb = 0.45359237 kg and 1 in = 2.54 cm. Results are rounded to whole numbers, or one decimal for BMI.
What is not included
Body composition, medical conditions, pregnancy, medications and children and teens.
Corrections
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