Skip to content
Lizely

Calorie Calculator

Estimate how many calories you need per day to lose, maintain, or gain weight — Mifflin-St Jeor TDEE, computed instantly in your browser with nothing uploaded.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Choose your sex, then enter your age, weight in kilograms, and height in centimeters.
  2. 2.Pick the activity level that best matches your typical week, from sedentary to extra active.
  3. 3.Read your maintenance calories (TDEE) instantly, then switch the goal toggle to lose, maintain, or gain weight to see your daily calorie target.

About Calorie Calculator

The Calorie Calculator estimates your Total Daily Energy Expenditure (TDEE) — the number of calories your body burns in a full day — and turns it into a practical daily calorie target for losing, maintaining, or gaining weight. Unlike a plain BMR calculator, which reports only the resting energy your body uses while completely at rest, this tool goes two steps further: it scales that resting figure by how active you are and then adjusts for your weight goal, so the final number reflects what you should actually eat each day. Everything runs locally in your browser; your age, weight, and height never leave your device.

Methodology: the calculation starts from the Mifflin-St Jeor equation, published in 1990 and widely regarded as the most accurate general-population predictor of basal metabolic rate (BMR). For men, BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age(years) + 5; for women the final constant is -161 instead of +5. That resting figure is multiplied by an activity factor to produce TDEE. The five standard multipliers are 1.2 for sedentary (little or no exercise), 1.375 for lightly active (1-3 days per week), 1.55 for moderately active (3-5 days), 1.725 for very active (6-7 days), and 1.9 for extra active (hard daily training or a physical job). TDEE is your maintenance level — eat that much and your weight tends to hold steady.

Weight goals are handled with a calorie deficit or surplus. To lose weight the tool subtracts about 500 calories per day from your TDEE, and to gain weight it adds about 500. A daily change of roughly 500 calories corresponds to about 0.45 kg (1 pound) per week, since a pound of body fat stores roughly 3,500 calories. To keep targets safe, the result is never allowed to drop below 1,000 calories per day; very low intakes should only be attempted under professional supervision.

Why TDEE beats BMR alone: two people with identical resting metabolisms can have very different real-world needs. A desk worker and a construction worker with the same BMR might burn hundreds of calories apart once movement, exercise, and the thermic effect of food are counted. The activity multiplier captures that gap, which is why nutrition planning is built on TDEE rather than resting numbers. Because these multipliers are population averages, treat the output as a well-grounded starting point: track your weight for two to three weeks and nudge intake up or down if the trend does not match your goal.

This calculator is provided for general information only. It does not account for body composition, pregnancy, medical conditions, medications, or individual metabolic variation, and it is not medical or nutritional advice. Always consult a qualified doctor or registered dietitian before starting any diet or making significant changes to your calorie intake.

Methodology & sources

Daily calorie needs are estimated as TDEE = BMR x activity factor, where BMR uses the Mifflin-St Jeor equation (1990): men = 10*kg + 6.25*cm - 5*age + 5; women = 10*kg + 6.25*cm - 5*age - 161. Activity factors are the standard five multipliers (sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extra active 1.9). Weight-goal targets apply a fixed 500 kcal/day deficit for weight loss or a 500 kcal/day surplus for weight gain (about 0.45 kg / 1 lb per week, based on the ~3,500 kcal-per-pound convention), with results clamped to a 1,000 kcal/day floor for safety. Assumptions: activity multipliers are population averages, body composition and medical factors are not modeled, and the 3,500 kcal/lb rule is an approximation. This is an estimate for general information only and is not medical or nutritional advice; consult a qualified professional before changing your intake.

Frequently asked questions

What is the difference between this calorie calculator and a BMR calculator?
A BMR calculator reports only your basal metabolic rate — the calories you burn completely at rest. This calorie calculator takes that resting figure, multiplies it by an activity factor to get your Total Daily Energy Expenditure (TDEE), and then adjusts for a weight goal, so it tells you roughly how many calories to actually eat each day rather than just what your body burns at rest.
How are my daily calories and weight-goal targets calculated?
BMR uses the Mifflin-St Jeor equation (men: 10*kg + 6.25*cm - 5*age + 5; women: the same minus 161 at the end). TDEE is BMR multiplied by an activity factor from 1.2 (sedentary) to 1.9 (extra active). To lose weight the tool subtracts about 500 calories per day and to gain it adds about 500, which is roughly 0.45 kg (1 lb) per week. Targets never fall below 1,000 calories per day.
Is this calorie estimate medical advice?
No. It is an estimate for general information only and does not account for body composition, pregnancy, medical conditions, medications, or individual metabolic variation. It is not medical or nutritional advice — always consult a qualified doctor or registered dietitian before starting a diet or significantly changing your calorie intake.

Related tools

Calculators guides

View all