Formula
- Mifflin-St Jeor
- Current standard, considered the most accurate (recommended)
- Harris-Benedict (revised)
- Classic formula revised in 1984
- Katch-McArdle (simplified)
- Estimates lean mass from weight (~85%) — sex-independent
Frequently asked questions
Basal Metabolic Rate (BMR) is the minimum number of calories your body uses at rest to maintain vital functions such as breathing, blood circulation, body temperature, and cellular activity. It represents the energy you would burn lying down all day without moving.
BMR is your calorie burn at rest. TDEE (Total Daily Energy Expenditure) is the total daily calorie burn, adding BMR to the calories spent on physical activities and daily tasks. TDEE is calculated by multiplying BMR by an activity factor between 1.2 (sedentary) and 1.9 (very active).
The Mifflin-St Jeor formula is considered the most accurate for most people and is recommended by the Academy of Nutrition and Dietetics in the US. The revised Harris-Benedict (1984) is a classic alternative. Katch-McArdle tends to be more accurate for people who know their body fat percentage.
To lose weight, eat about 500 kcal less than your daily TDEE, which tends to produce a loss of around 0.5 kg (1 lb) per week. The calculator already shows this suggestion automatically, along with values for maintaining weight and gaining muscle.
Yes. The ToolboxHub BMR and TDEE calculator is 100% free, runs directly in your browser, and requires no signup or installation. The data you enter is not stored on any server.
No. The values are estimates based on statistical formulas and do not account for individual factors such as detailed body composition, genetics, health conditions, or medications. For a personalized eating plan, consult a nutritionist or doctor.