If you’ve ever wondered “how many calories should I eat to lose weight,” the honest answer is: it depends on your TDEE. Your total daily energy expenditure is the number of calories your body burns in a day. Eat below it and you lose weight; eat at it and you stay put. Get the number right, and weight loss becomes arithmetic instead of guesswork. Here’s how to calculate your TDEE and turn it into a weight-loss plan that actually works.
Want the number in seconds? Use our free TDEE Calculator — enter your age, gender, height, weight, and activity level, and you’ll get your TDEE plus your exact cut, maintain, and bulk calorie targets.
Step 1: Understand What TDEE Actually Is
TDEE (total daily energy expenditure) is every calorie you burn in 24 hours, added up from four sources: your basal metabolic rate (BMR, the energy cost of keeping you alive at rest), the thermic effect of food (digesting what you eat costs energy too), non-exercise activity like walking, standing, and fidgeting, and your planned workouts.
The surprise for most people is the ratio. Your workouts might burn 300–500 calories, but your BMR alone burns well over a thousand — it typically accounts for 60–70% of TDEE. That’s why the math matters more than the gym: you can’t out-train a number you don’t know.
Step 2: Calculate Your BMR
The most validated formula for the general population is the Mifflin-St Jeor equation:
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Example: A 32-year-old woman, 68 kg, 165 cm tall:
BMR = (10 × 68) + (6.25 × 165) − (5 × 32) − 161 = 680 + 1,031.25 − 160 − 161 = 1,390 calories
That’s what her body burns just keeping the lights on — before she gets out of bed.
Step 3: Multiply by Your Activity Level
TDEE = BMR × an activity multiplier. The standard five levels are:
- Sedentary (1.2) — desk job, little or no exercise
- Lightly active (1.375) — light exercise 1–3 days/week
- Moderately active (1.55) — moderate exercise 3–5 days/week
- Very active (1.725) — hard exercise 6–7 days/week
- Extra active (1.9) — physical job or training twice daily
Continuing the example: our 32-year-old does three moderate gym sessions a week and works a desk job, so she’s moderately active: TDEE = 1,390 × 1.55 = 2,155 calories per day.
Warning: this step is where almost everyone goes wrong. People systematically overestimate how active they are — a desk job plus three workouts is moderately active at best, not very active. When in doubt, pick the lower level. A wrong choice here can inflate your TDEE by 300+ calories, quietly erasing your deficit.
Step 4: Set Your Deficit
To lose fat, eat below your TDEE. The standard guideline: a 500-calorie daily deficit produces roughly 1 lb of fat loss per week (a pound of fat holds about 3,500 calories). For our example: 2,155 − 500 = 1,655 calories per day.
Don’t go bigger by default. Aggressive deficits of 700–1,000+ calories work faster but cost more muscle, spike hunger hormones, and are the reason most crash diets end in a rebound. A moderate deficit you can sustain for months beats a brutal one you abandon in two weeks. Never eat far below your BMR — below that line you’re under-fueling basic body functions.
Step 5: Track, Then Adjust
No formula is exact to the calorie — individual metabolism varies by 10–15%. Your TDEE is a starting point, and your scale is the referee. Track your weight under consistent conditions (morning, after the bathroom, before eating) and look at the weekly average, not daily noise — water retention can swing the scale 2–3 lbs overnight.
After 2–3 weeks: if the trend matches your target, change nothing. If weight isn’t moving, cut another 100–200 calories. If it’s dropping too fast (more than ~1% of body weight per week) and you’re constantly fatigued, add 100–200 back. And recalculate your TDEE every 5–10 lbs lost — a lighter body burns fewer calories, so yesterday’s deficit quietly becomes today’s maintenance.
Common TDEE Mistakes That Stall Weight Loss
- Inflating activity level. The #1 error. Be honest about your job’s inactivity and your actual workout intensity.
- “Eating back” exercise calories. Fitness trackers overestimate workout burn by 20–40%. If you log exercise and eat the calories back, you’re probably erasing your deficit.
- Ignoring the weekend. Five perfect days plus a 4,000-calorie weekend averages out to no deficit at all. Consistency across all seven days matters.
- Chasing the lowest number. Eating as little as possible isn’t a strategy — it stalls hormones, sleep, and adherence. The right deficit is the largest one you can sustain, not the largest one that exists.
- Forgetting liquid calories. Coffees, sodas, and alcohol can add hundreds of calories daily without registering as “food.” Track everything for at least two weeks to see the truth.
The Bottom Line
Calculating TDEE for weight loss takes five steps: compute your BMR with Mifflin-St Jeor, multiply by an honest activity factor, subtract a 500-calorie deficit, track your weekly weight trend, and adjust as you go. Do that, and you’ve replaced diet guesswork with a number you can actually manage.
Ready for your number? The TDEE Calculator does all of this instantly — your BMR, your TDEE, and your cut, maintain, and bulk targets on one screen. Pair it with the BMR Calculator if you want your resting burn number on its own, and the BMI Calculator to see where your weight stands for your height.
Health disclaimer: This article is for informational purposes only, not medical advice. Consult a qualified healthcare professional before starting any weight-loss plan.
Try Our Free Calculators
Put this guide into practice with our free tools: Tdee Calculator, Calorie Calculator, Bmr Calculator.