Calorie Calculator
Find your daily calorie target from your BMR, activity level, and goal — plus a macro split and a 12-week weight projection. Everything runs in your browser.
Recommended macro splits
Weight projection (next 12 weeks)
| Week | Projected weight | Change |
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How the calorie calculation works
Two numbers do the heavy lifting: your BMR and your TDEE.
Your BMR (basal metabolic rate) is the energy your body burns at complete rest — powering your organs, brain, and cell repair even if you stayed in bed all day. This tool finds it with the Mifflin-St Jeor equation, the formula dietitians most often reach for because it tracks measured metabolism more closely than the older Harris-Benedict method.
Your TDEE (total daily energy expenditure) is your BMR multiplied by an activity factor — 1.2 if you sit most of the day, up to 1.9 for a training athlete. TDEE is the number you actually eat to: match it to hold your weight, drop below it to lose, or sit above it to gain.
Turning calories into a goal
A pound of body fat stores roughly 3,500 calories, so a daily deficit of about 500 calories trends toward one pound of loss per week. The goal selector applies that adjustment for you, and the projection table shows where a steady deficit or surplus would put your weight over 12 weeks — a realistic trend line, not a guarantee.
How to use your results
Start with the daily calorie target and hold it for two to three weeks, then adjust based on the scale trend rather than any single day. Keep protein high — 1.6 to 2.2 g per kilogram of bodyweight — to protect muscle whether you are cutting or bulking. To turn a specific recipe into calories per serving, run it through the recipe nutrition calculator.
Frequently asked questions
How many calories do I need per day?
Your daily need is your TDEE — the calories you burn at your activity level. This tool calculates your BMR with Mifflin-St Jeor, then multiplies by an activity factor from 1.2 (sedentary) to 1.9 (very active). Most adults land between 1,800 and 2,600 calories to maintain their weight.
What is the difference between BMR and TDEE?
BMR is the energy your body burns at complete rest just to stay alive. TDEE is your BMR multiplied by an activity factor, so it also counts movement, exercise, and digestion. TDEE is the number you eat to, not BMR.
Is the Mifflin-St Jeor equation accurate?
Yes — studies rate it as the most accurate BMR formula for the general population, usually within about 10 percent of measured values, and more reliable than Harris-Benedict. Body composition, genetics, and hormones still cause variation, so treat the result as a strong starting estimate.
How do I use these calories for weight loss?
Eat below your TDEE. A deficit of about 500 calories a day loses roughly one pound (0.45 kg) per week, since a pound of fat holds about 3,500 calories. Choose the -500 goal, keep protein high, and reassess after two to three weeks.
Which macro split should I pick?
Balanced (30/40/30) suits most people. Choose High Protein when cutting or building muscle. Low Carb or Keto can help appetite control but are not required for fat loss — total calories drive weight change. Aim for 1.6 to 2.2 g of protein per kg of bodyweight.
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