Calorie (BMR/TDEE) Calculator

This calorie calculator estimates how many calories your body burns in a day, then turns that into a daily target for your goal. It takes under a minute. "Calorie" and "kcal" mean the same thing here.

Quick start (Simple mode)

1. Pick a unit system. Imperial (lb, ft/in) or metric (kg, cm).
2. Enter age, sex, height and weight. If you want context for those numbers first, the BMI calculator takes the same height and weight inputs.
3. Choose the activity level that matches your real week. Pick what you actually did over the last month, not what you plan to do.
4. Read your TDEE. That is the estimated number of calories you burn per day, so eating it should keep your weight steady.

What Advanced mode adds

• BMR formula choice: Mifflin-St Jeor (default), Revised Harris-Benedict (1984), or Katch-McArdle, which uses body fat %.
• Goal: maintain, mild loss (−250), loss (−500), extreme loss (−750), mild gain (+250) or gain (+500) calories per day.
• Macro split: balanced 30/40/30, high protein 40/30/30, low carb 30/20/50, keto-style 25/5/70, or a custom split (protein/carbs/fat).
• Target weight (optional): unlocks a week-by-week projection timeline.

Results include your daily calorie target, BMR, TDEE, protein, carbs and fat in grams, and a goal-comparison table or weight projection.

BMR formulas, side by side

BMR is the energy your body uses at rest. Each formula below estimates it in a slightly different way. The numbers use one example man: 35 years old, 80 kg, 180 cm, and 20% body fat for Katch-McArdle.

Formula	Inputs	Example man (cal/day)	Best for
Mifflin-St Jeor (default)	Age, sex, height, weight	1,755	Most people; no body fat needed
Revised Harris-Benedict (1984)	Age, sex, height, weight	1,825	Cross-checking Mifflin-St Jeor with a second equation
Katch-McArdle	Lean body mass (weight and body fat %)	1,752	People who know their body fat percentage reliably

The math

• Mifflin-St Jeor: men 10W + 6.25H − 5A + 5; women 10W + 6.25H − 5A − 161 (W = kg, H = cm, A = years). Example: 10×80 + 6.25×180 − 5×35 + 5 = 1,755.
• Revised Harris-Benedict: men 88.362 + 13.397W + 4.799H − 5.677A; women 447.593 + 9.247W + 3.098H − 4.330A. Example: 1,825.
• Katch-McArdle: 370 + 21.6 × lean body mass. At 20% body fat, lean mass is 64 kg, so 370 + 21.6×64 = 1,752.

The three results sit 73 calories apart, well inside the ±10% error these estimates carry. For a second view, MyTDEECalculatorPro has a side-by-side comparison of the three BMR formulas.

Which one to choose

Start with Mifflin-St Jeor. It needs only the basics and doesn't depend on a guess about your body.

Switch to Katch-McArdle only if your body fat figure comes from a source you trust. It ignores age, sex and height, so a poor body fat estimate carries straight into your result.

BMR vs TDEE

BMR is what you burn lying still. TDEE is what you burn in a full day: BMR plus walking, working, exercise and digesting food. The formula is simple: TDEE = BMR × activity multiplier.

Activity level	Multiplier	In plain English	Example man's TDEE
Sedentary	×1.2	Mostly sitting, little exercise	2,106
Lightly active	×1.375	Light exercise a few days a week	2,413
Moderately active	×1.55	Moderate exercise most days	2,720
Very active	×1.725	Hard exercise most days	3,027
Extra active	×1.9	Very hard exercise or a physical job plus training	3,335

Activity is the noisiest input

Your BMR comes from measurements. Your activity level comes from your own judgment, and that's where most of the error enters. Three gym sessions a week plus a desk job is not "very active."

If you're torn between two levels, pick the lower one. Then compare your actual weight trend over a few weeks and adjust.

Eating at your BMR is not a small deficit

For the example man, eating at his BMR means 1,755 calories against a 2,720 TDEE. That is a 965-calorie daily gap, about 35% below maintenance. By the usual 3,500-calorie rule it works out to nearly 2 lb a week, far more than the −500 setting.

The more active you are, the bigger that gap gets. Set goals from TDEE, not BMR. FitnessVolt also publishes a TDEE vs BMR explained page if you want another take.

Goal offsets

The calculator subtracts or adds a fixed number of calories to your TDEE. Here is the example man (TDEE 2,720):

Goal	Offset	Daily target
Extreme loss	−750	1,970
Loss	−500	2,220
Mild loss	−250	2,470
Maintain	0	2,720
Mild gain	+250	2,970
Gain	+500	3,220

The 3,500-calorie rule, and its limits

A common rule of thumb says about 3,500 calories equals one pound of body weight. A 500-calorie daily deficit adds up to 3,500 a week, or roughly 1 lb. A 250-calorie deficit is about half a pound.

Real bodies are not perfectly linear. As you lose weight your TDEE drops, and your body can adapt by burning less. Treat the weekly projection as a guide, not a promise.

Macro math

Calories per gram: protein 4, carbs 4, fat 9. Each macro's grams = (target calories × its percentage) ÷ 100 ÷ calories per gram.

Example: the −500 target of 2,220 calories on the balanced 30/40/30 split (protein/carbs/fat).

• Protein: 2,220 × 30% = 666 calories ÷ 4 = 166.5, shown as 167 g.
• Carbs: 2,220 × 40% = 888 calories ÷ 4 = 222 g.
• Fat: 2,220 × 30% = 666 calories ÷ 9 = 74 g.

If you tweak a split by hand, you can use the percentage calculator to work out what share of your calories comes from protein. The presets are starting points, not personalized nutrition advice.

Safe minimums

The calorie calculator shows a safety warning if your target falls below 1,500 calories a day for men or 1,200 for women. Targets below those floors need medical supervision.

These tools also can't account for medical conditions, medications, pregnancy or metabolic adaptation.

These are estimates, not medical advice — if you have a medical condition, take medication, or are pregnant, talk to a clinician or dietitian before changing how you eat.