About the Calorie Calculator
Tezmy's Calorie Calculator estimates how much energy your body uses each day and how many calories to eat to reach your goal. It calculates your basal metabolic rate (BMR) with the Mifflin–St Jeor equation, which research shows is the most accurate for most adults, then multiplies it by your activity level to find your maintenance calories (TDEE). You'll see daily targets for losing, keeping or gaining weight at a steady pace, with a warning when a target drops below the usual safe minimum.
Updated October 2026
How to use the Calorie Calculator
- 1Choose your sex and units.
- 2Enter your age, height and weight.
- 3Pick the activity level that fits a typical week.
- 4Read your maintenance calories and the targets for your goal.
BMR and TDEE in simple words
BMR (basal metabolic rate) is the energy your body uses at complete rest, just to breathe, keep warm and keep your organs working. TDEE (total daily energy expenditure) adds everything you do in a day: walking, working, exercise. Eating about your TDEE keeps your weight stable.
Choosing your activity level
Most people overestimate their activity. If you're unsure, pick the lower level and adjust after a few weeks.
- Sedentary: little or no exercise, like a desk job.
- Light: exercise 1–3 days a week.
- Moderate: exercise 3–5 days a week.
- Active: hard exercise 6–7 days a week.
- Very active: a physical job or training twice a day.
Losing or gaining weight steadily
A common guide is that a daily deficit of about 500 calories leads to roughly 0.5 kg (about 1 lb) of weight loss per week, though real bodies vary. Slow, steady change is easier to keep up and protects muscle. Very low targets can leave you short of nutrients, so the calculator warns when a goal drops below the usual safe minimum.
Use the result as a starting point
Every calculator gives an estimate. Track your weight for two to three weeks while eating the suggested calories, then adjust up or down. If you are pregnant, breastfeeding, under 18, an athlete or have a medical condition, ask a doctor or dietitian for advice that fits you. Your calorie target works best next to your body numbers, so check your BMI Calculator result too. If you are planning meals around a birthday goal or a race, the Age Calculator and the Unit Converter (for pounds, kilograms, feet and centimetres) help you fill in the right inputs.
Features
- Mifflin–St Jeor BMR
- Maintenance calories (TDEE)
- Targets to lose or gain weight
- Metric and US units
- Safe-minimum warnings
- Private: nothing is stored
Frequently asked questions
What's the difference between BMR and TDEE?
BMR is the energy your body uses at complete rest. TDEE (total daily energy expenditure) adds everything you do in a day. Eating at your TDEE keeps your weight stable.
How many calories should I cut to lose weight?
About 500–550 calories a day below maintenance leads to roughly 0.5 kg (1 lb) of loss per week, a pace most experts consider sustainable.
Which activity level should I choose?
Pick based on a typical week, including work. Most office workers who exercise a few times a week fit “Light” or “Moderate”. Overestimating activity is the most common mistake.
How accurate is this?
It's an estimate that's usually within about 10% for most people. Track your weight for a few weeks and adjust by 100–200 calories if needed.
Is it suitable for everyone?
It's for healthy adults. Children, pregnant or breastfeeding women, athletes and people with medical conditions should get advice from a professional.
How many calories do I need a day?
Enter your age, sex, height, weight and activity level. Your maintenance calories (TDEE) is the amount that keeps your weight about the same.
Why the Mifflin–St Jeor equation?
Studies comparing the common formulas found Mifflin–St Jeor to be the most accurate for most healthy adults, so it's the one many dietitians use.
Does it work in pounds and feet?
Yes. Switch to US units to enter your height in feet and inches and your weight in pounds.