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Calorie Calculator

A free online calorie calculator that estimates your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor formula, then shows how many calories to eat per day to maintain, lose, or gain weight at different rates.

How your calorie needs are calculated

The calculator first estimates your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation - the calories your body burns at complete rest just to keep your organs functioning. It then multiplies BMR by an activity multiplier based on how much you move during the day, producing your Total Daily Energy Expenditure (TDEE), or maintenance calories.

Why activity level matters so much

Two people with identical age, height, and weight can have very different calorie needs depending on activity level. A sedentary lifestyle uses a multiplier of 1.2, while a very physically demanding job or daily hard training can push the multiplier to 1.9 - nearly 60% more calories than the sedentary estimate.

Reading the weight loss and gain table

Each row below your maintenance calories represents a calorie target for a specific weekly rate of change, based on the standard estimate that one pound of body weight is roughly equal to 3,500 calories. Mild weight loss (250 kcal/day deficit) targets about 0.5 lb per week; extreme weight loss (1,000 kcal/day deficit) targets about 2 lb per week, the generally recognized upper limit for safe, sustainable weight loss.

Common Mistakes to Avoid

Treating the result as an exact number rather than an estimate

Solution:

BMR formulas are population averages - your actual metabolism can vary by several hundred calories depending on genetics, muscle mass, and other factors. Use the result as a starting point and adjust based on real-world progress.

Choosing an activity level that's more aspirational than actual

Solution:

Pick the activity level that matches your typical week, not your ideal week - overestimating activity is the most common reason a calorie target doesn't produce the expected results.

Cutting calories too aggressively

Solution:

A deficit larger than about 1,000 kcal/day, or a target below roughly 1,200 kcal/day (women) or 1,500 kcal/day (men), can be hard to sustain and is not usually recommended without medical supervision.

Not recalculating as your weight changes

Solution:

BMR drops as body weight decreases, so a calorie target that worked at your starting weight will gradually become too high - recheck the calculator every 10-15 lb of change.

Ignoring protein and nutrient quality in favor of calories alone

Solution:

Total calories determine weight change, but the mix of protein, carbs, and fat affects hunger, muscle retention, and how sustainable the plan feels.

Confusing calories burned exercising with your daily calorie budget

Solution:

The activity multiplier already accounts for your typical exercise - manually adding a workout's calories on top of an already-active multiplier double-counts the same energy use.

Frequently Asked Questions

This calculator uses the Mifflin-St Jeor equation: for men, BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5; for women, BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161.
Total Daily Energy Expenditure is your BMR multiplied by an activity factor, representing the total calories you burn in a typical day including movement and exercise. It's also called your maintenance calorie level.
Eating below your TDEE creates a deficit. A 500 kcal/day deficit targets about 1 lb of loss per week, since one pound of body fat is roughly 3,500 calories.
The table shows a range of common rates - from mild (0.5 lb/week) to extreme (2 lb/week) - so you can pick a pace that fits your goals and how sustainable a given calorie deficit or surplus feels.
The Mifflin-St Jeor formula is validated for the general population but tends to underestimate BMR for very muscular individuals, since it doesn't account for body composition directly.
No - this is a general population estimate. Pregnant, breastfeeding, or medically supervised individuals should follow guidance from a healthcare provider instead.
No - every calculation runs locally in your browser. Nothing you enter is uploaded, logged, or stored on any server.

Free Online Calorie Calculator

Find out how many calories you burn each day and how many you should eat to maintain, lose, or gain weight. Enter your age, height, weight, and activity level for an estimate based on the Mifflin-St Jeor formula, one of the most accurate BMR equations available.

What You Get

  • Your Basal Metabolic Rate (BMR) - calories burned at rest
  • Your Total Daily Energy Expenditure (TDEE) - your maintenance calories
  • A full table of calories needed for mild, moderate, and extreme weight loss or gain
  • Support for both standard (lb, ft/in) and metric (kg, cm) units

Who Uses This Calculator

Anyone starting a diet or fitness plan, tracking macros, or simply curious how many calories their body needs at rest and with daily activity.