Calorie and BMR Calculator

How to use Calorie and BMR Calculator

1. Choose metric or imperial units and enter your age, sex, height and weight.
2. Select the activity level that best matches a normal week.
3. Choose a daily deficit or surplus size.
4. Read your BMR, maintenance calories and the two target figures.

BMR, TDEE and calorie targets

Your body burns energy all day. Basal metabolic rate (BMR) is the portion used just to keep systems running at rest. Total daily energy expenditure (TDEE) adds the energy you use for movement, exercise and everyday activity, so it is the figure that matters for maintaining weight. Eating around your TDEE tends to hold your weight steady; eating less tends to reduce it, and eating more tends to increase it.

This tool uses the Mifflin-St Jeor equation, a commonly used estimate for adults, and multiplies BMR by an activity factor to estimate TDEE. The deficit and surplus options simply subtract or add a fixed number of calories to maintenance.

Formula and worked example

BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men, or − 161 for women. TDEE = BMR × activity factor, using 1.2 (sedentary), 1.375 (light), 1.55 (moderate), 1.725 (very active) or 1.9 (extra active). These factors are common conventions, not exact measurements.

Example: a 30-year-old man, 175 cm, 75 kg. BMR = 750 + 1,093.75 − 150 + 5 = 1,698.75 kcal. With moderate activity, TDEE = 1,698.75 × 1.55 ≈ 2,633 kcal. A 500 kcal deficit target is about 2,133 kcal a day, and a rough rule of thumb of 7,700 kcal per kg suggests about 0.45 kg a week, though real changes vary.

Medical disclaimer, tips and limits

This calculator is for general information only and is not medical advice. It is meant for healthy adults and should not be used during pregnancy, while breastfeeding, for children and teenagers, or if you have a medical condition, an eating disorder or take medication that affects weight, without professional guidance.

• Be honest about activity; most people overestimate it.
• Track weight over two to three weeks before adjusting calories.
• Food quality, protein, sleep and strength training matter as well as calorie totals.
• Never eat below your estimated BMR for long periods without medical supervision.
• Your information stays in your browser and is never uploaded.

Why use this calorie and bmr calculator tool

• Mifflin-St Jeor equation. A widely used formula for adult resting energy use.
• Metric or imperial. Use cm and kg, or feet, inches and pounds.
• Activity multiplier. Five levels convert BMR into maintenance calories.
• Safety check. Warns if a deficit target falls below your estimated BMR.

Frequently asked questions

More free tools