FREE CALCULATOR · HEALTH

TDEE & Daily Calorie Calculator

How many calories can you actually eat? This calculator estimates your resting burn with the Mifflin-St Jeor equation, scales it by your real activity level, and sets daily targets for losing, maintaining, or gaining weight — with macros included.

What is your daily calorie target?

Your resting burn, your activity-scaled total, and the calorie line for your goal — plus the protein, fat, and carb split that fits it.

Sex

The Mifflin-St Jeor equation uses different constants for men and women.

Age

10 to 100. Metabolism slows a little every decade after 30.

Height — feet

Feet portion of your height.

Height — inches

Remaining inches (0–11).

Weight (lb)

Your current body weight. Re-run the calculator every 10–15 lb of change.

Activity level

Be honest — most people pick one level too high. Exercise is the small slice; daily movement is the big one.

Goal

A 500-calorie daily shift moves roughly a pound a week (3,500 calories per pound).

Your daily calorie target 2,724 cal/day Maintain weight · BMR 1,758 × 1.55 (Moderately active).

Lose ~1 lb/week2,224 cal/dayLose ~1 lb/week · 500 below TDEE

1,000 cal/daybetween the two targets

Gain ~1 lb/week3,224 cal/dayGain ~1 lb/week · 500 above TDEE

Enter your numbers above to run the calculation.

How it works: BMR (Mifflin-St Jeor) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men / − 161 for women. TDEE = BMR × your activity factor. Your target = TDEE + your goal offset. Macros split on the target: protein 0.8 g per lb of body weight, fat 25% of calories ÷ 9, and the rest as carbs.

How the TDEE math works

Your body burns calories in two buckets: keeping you alive (BMR — breathing, brain, organs, body heat) and everything you do (TDEE adds movement and exercise on top). Most diet math goes wrong by guessing at the total; the standard approach is to compute the resting number properly, then scale it by honest activity.

The formulas

BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women)
TDEE = BMR × activity factor (1.2–1.9)
target = TDEE + goal offset (−500 to +500)
protein = 0.8 g × body weight (lb) · fat = 25% of calories ÷ 9 · carbs = the rest ÷ 4

Mifflin-St Jeor is the equation most dietitians reach for: validated against measured metabolic rates, it beats the older Harris-Benedict formula for typical adults without a lab test.

Worked example: 35-year-old man, 5'10", 180 lb, moderately active

1. Convert units: 180 lb ÷ 2.20462 = 81.65 kg; (5 × 12 + 10) = 70 in × 2.54 = 177.8 cm.

2. BMR: 10 × 81.65 + 6.25 × 177.8 − 5 × 35 + 5 = 816.5 + 1,111.25 − 175 + 5 = ≈ 1,758 cal/day at complete rest.

3. TDEE: 1,758 × 1.55 (moderately active) = ≈ 2,724 cal/day — the maintenance target.

4. Goal targets: lose ~1 lb/week → 2,224; maintain → 2,724; gain ~1 lb/week → 3,224. Macros at maintenance: protein 144 g (0.8 × 180), fat 76 g (25% of calories), carbs 366 g.

Where this comes in handy

Starting a cut: eat the "lose ~1 lb/week" target for two weeks, then adjust by the trend — not the calculator — if weight is not moving.
Finding maintenance after a diet: the maintain target is your new baseline; most people regain because they return to old eating, not because the number was wrong.
Fueling training: pair the calorie target with the sleep cycle calculator — under-sleeping tanks the hormones that regulate hunger.
Setting protein first: the 0.8 g/lb protein line protects muscle while cutting; build meals around it and let carbs flex.
Sanity-checking a meal plan: if a plan's calories sit far below your BMR, it is a crash diet wearing a costume.
Tracking progress honestly: the percentage calculator turns pounds lost into the percentage that actually matters for goal-setting.

TDEE and calories — frequently asked questions

What is the difference between BMR and TDEE?

BMR (basal metabolic rate) is what you would burn lying motionless in a warm room for 24 hours — typically 60–75% of your total. TDEE (total daily energy expenditure) adds everything else: daily movement, exercise, digesting food, even fidgeting. BMR is the engine size; TDEE is the fuel bill.

How accurate is the Mifflin-St Jeor equation?

For typical adults it lands within about 10% of lab-measured metabolic rate — the best of the simple equations, and the one most dietitians use. It struggles at the extremes: very muscular, very lean, or obese bodies, where body composition matters more than weight alone. Treat the result as a starting line, then steer by two weeks of real data.

Why does 500 calories a day equal a pound a week?

A pound of body fat stores roughly 3,500 calories of energy. Eat 500/day under your TDEE and the weekly deficit is 3,500 — about a pound. It is a rule of thumb, not physics: as you lose weight your TDEE drops, water shifts, and the rate slows, which is why the calculator tells you to re-run it every 10–15 lb.

Should I eat back my exercise calories?

Usually not, or only half. Fitness trackers famously overcount burn — often by 30% or more — and your activity factor already includes your training. Eating back the full tracked amount routinely erases the deficit. Exception: genuinely huge endurance days (long runs, all-day hikes), where under-fueling wrecks recovery.

When should I recalculate my TDEE?

Every 10–15 lb of weight change, every few months, or whenever progress stalls for 3+ weeks. BMR falls as weight falls — a TDEE computed at 180 lb is simply wrong at 165 lb. Also re-run it if your activity genuinely changes (new job, new training block, injury).

Where do the protein, fat, and carb numbers come from?

Protein at 0.8 g per lb of body weight is the widely used floor for preserving muscle (lifters often go to 1 g/lb). Fat at 25% of calories keeps hormones happy without crowding out other macros. Carbs fill whatever calories remain — they are the flexible fuel, not the enemy.