Everything in this guide
Updated November 10, 2026.
The guide
Everything you need to know about the calories you burn
Where your calories go, why calculators disagree, your activity level from your steps, how much to eat to lose, why a deficit stalls, and how to find your real number.
Where your calories go
Your day's calories go four places, resting burn, digesting food, everyday movement and exercise. What each one costs, and why the workout is often the smallest.
The formulas, and why calculators disagree
Four formulas estimate your resting burn, from 1918 to 1991. How each was built, how far off it can be for you, which to use, and why your activity level matters more.
Your activity level, from your steps
Calculators ask if you're sedentary or moderately active. Your step count answers it better than your gym schedule. The step bands, what they add, and the gym trap.
How many calories to eat to lose weight
Start about 500 calories a day under maintenance and lose 0.5 to 1 percent of your weight a week. Never go under your resting burn, or 1,200 (women) or 1,500 (men).
Why you're not losing weight in a deficit
If the scale won't move, your deficit is smaller than you think. Each gap sized in calories, from unlogged food and eaten-back workouts to weekends and water.
Is your watch's calorie number right?
Watches get steps and heart rate close and miss calories by 20 to 90 percent in lab tests. What the number is made of, active against total calories, and how to use it.
Does metabolism slow with age?
Not until about 60. Adjusted for body size, daily burn holds steady from 20 to 60, then falls about 0.7 percent a year. What changes earlier is muscle and movement.
Measure your real TDEE in four weeks
Four weeks of food logs and morning weigh-ins give you a maintenance number that's yours, not a formula's. The method, the arithmetic, the traps, and when to redo it.
Questions
Are Fitbit, Garmin and Oura calories accurate?
No brand is accurate for calories. A review of 158 studies found Fitbit, Garmin and others often good for steps and heart rate, and none accurate for energy burned.
Do women burn fewer calories than men?
Yes, mostly from size and muscle: the average American woman burns about 450 fewer a day than the average man under 5,000 steps. Matched for body makeup, no gap.
Does dieting slow your metabolism?
A little, and mostly because you're smaller. After a 30-pound loss, the extra dip was about 90 calories a day, and about 40 after a month at a steady weight.
Does muscle burn more calories than fat?
Yes, about 3 times as much, but it's small: about 6 calories a day per pound of muscle at rest, against 2 for fat. 5 pounds of new muscle adds about 30 a day.
Does sleep affect how many calories you burn?
A short night burns about 5% more, since you're awake longer. But people ate more than that and gained weight, and dieters on short sleep lost less fat.
How accurate are TDEE calculators?
The formula part lands within 10% for about 4 people in 5. The activity level you pick adds more error than the formula. Use the answer as a range, then check it.
How accurate is calorie counting?
Rough. Careful food recalls ran 12 to 20% low in a lab-checked study, and labels can run 20% high. Counting still works if you're consistent and check your scale.
How big should my calorie deficit be?
Start at about 500 a day, the low end of the US guideline's 500 to 750. Or size it to you: 0.5 to 1% of your weight a week. Never below your floor.
How many calories do 10,000 steps burn?
A few hundred more than sitting, set mostly by your weight: about 240 to 320 at 150 pounds and 400 to 530 at 250. A heavier body pays more per step.
How many calories do I burn a day?
About 1,950 to 2,380 for the average American man and 1,540 to 1,880 for the average woman under 5,000 steps a day. At 7,500 to 9,999 steps, about 30% more.
How many calories do I burn doing nothing?
More than you'd guess: about 1,290 a day lying still for a 140-pound woman and 1,730 for a 180-pound man. That's about 54 to 72 calories an hour.
How many calories do I need to maintain my weight?
A range, not one number. Start at the middle of a calculator's range, then 4 weeks of meals and weigh-ins find yours. It drops about 10 a day per pound you lose.
How many calories does digestion burn?
About 5 to 15% of your day, roughly 100 to 300 calories at 2,000. Protein costs the most: 20 to 30% of its calories go to processing it, against 0 to 3% for fat.
How many calories does lifting weights burn?
About 150 to 300 above sitting for a 45-minute session at 180 pounds, set by how hard you go. Its bigger payoff is the muscle it keeps while you diet.
How many calories does walking a mile burn?
About 100 for a 180-pound person, or 75 more than sitting for those 20 minutes. Heavier people burn more. A mile run burns only about half again as much.
How many calories should I eat a day?
About what you burn: 1,540 to 1,880 for the average American woman and 1,950 to 2,380 for a man under 5,000 steps a day, more as you walk more. Eat less to lose.
How many calories should I eat to lose 2 pounds a week?
About 1,000 a day under your maintenance, and 500 for 1 pound a week. Two pounds only fits big or very active bodies. For many women it falls under the floor.
How much protein should I eat in a calorie deficit?
1.2 to 1.6 g per kg of your weight a day is typical, about 100 to 130 g at 180 pounds. Under that is too low, and many people are. Lean lifters need more.
How often should I recalculate my TDEE?
Every 10 pounds you lose, or every 4 weeks if you log. Each pound lost lowers your burn by about 10 calories a day, so 10 pounds takes about 100 off your deficit.
Is 1,200 calories a day too low?
For men, yes. For women it's the lowest to go without a doctor, and often lower than needed: the average American woman burns about 1,430 a day lying still.
Is 1,500 calories a day enough to lose weight?
For many women: it's about 210 under the average American woman's burn at under 5,000 steps a day and 710 at 7,500 to 9,999. For most men, it's under resting burn.
Is Apple Watch calorie burn accurate?
Not very. Across 56 studies its calorie estimate was off by about 28% on average, against 4% for heart rate and 8% for steps. Trust its steps more than its calories.
What activity level should I pick on a TDEE calculator?
Pick it from your daily steps, not your gym days. Under 5,000 is sedentary, 7,500 to 9,999 moderately active, 12,500 and up very active. Unsure? Take the lower one.
What is TDEE?
Total daily energy expenditure: every calorie you burn in a day, resting, digesting and moving. It's 1.2 to 1.9 times your resting burn, set mostly by your steps.
What's the difference between active and total calories?
Active calories are what you burn moving. Total adds your resting burn. Your TDEE is the total, so don't add active calories on top of a target built from it.
What's the difference between BMR and TDEE?
BMR is what you'd burn lying still all day. TDEE adds digesting and moving, 1.2 to 1.9 times BMR, set by your daily steps. You eat against TDEE. BMR is your floor.
Why am I gaining weight on 1,200 calories?
Almost always because you're eating more than the log says. In a classic 1992 study, people sure they ate under 1,200 ate nearly twice that. Their metabolism was normal.
Why am I not losing weight in a calorie deficit?
Usually the deficit is smaller than the math says. Careful food logs ran 12 to 20% low in a lab-checked study, and labels can run 20% high. Check 4 weeks of weigh-ins.
Why did my weight loss stop?
Mostly because you're smaller. Each pound lost lowers your burn by about 10 calories a day, so after 20 pounds your old deficit is about 200 smaller. Measure and reset.
Why does my weight go up and down every day?
Mostly water and food in transit, not fat. Weight runs higher after weekends and falls through the week. Average 7 mornings and compare week to week.
Myths
Should everyone eat 1,200 calories to lose weight?
No. 1,200 is the floor for women in the US obesity guideline, not a target for everyone. For most people it's a far bigger cut than they need. How to find yours.
Should you eat back your exercise calories?
No. Your usual workouts already belong in your maintenance, watches overstate them, and your body makes up part of what you burn. When to eat a little more anyway.
Does your metabolism slow down in your 30s?
No. Adjusted for body size, your daily burn holds steady from 20 to 60. The pounds of your 30s come from a small daily gap, about 100 calories for every 10 pounds.
Can some foods speed up your metabolism?
Yes, but barely. Protein costs the most to digest and caffeine raises your burn a little. Chili, green tea and fat-burning foods add tens of calories a day at most.
Does a pound of muscle burn 50 calories a day?
No. At rest a pound of muscle burns about 6 calories a day and a pound of fat about 2. Lifting still raises your burn, by more than the new muscle explains. The numbers.
Do six small meals a day speed up your metabolism?
No. Digesting food costs about 10 percent of what you eat, however you split it. In chamber tests six meals and two burned the same. Eat the pattern that keeps you full.
Is a slow metabolism why some people gain weight easily?
Not the way you think. Bigger bodies burn more, and people who say they can't lose usually have a normal burn for their size. People differ most in everyday movement.
Does starvation mode stop weight loss?
Not the way you think. Your burn drops a little more than your smaller size explains, about 40 to 90 calories a day. That shrinks a deficit and never reverses it.
Does your watch know how many calories you burned?
Sort of. It measures steps and heart rate closely and estimates calories from them. In lab tests that estimate missed by 20 percent or more. Good for comparing your days.
Tools
Calories from your steps
Your maintenance as a range, with every formula inside it.
Calories to lose
Your daily target, the date you get there, and the floor.
Measure your real TDEE
Four weeks of meals and weigh-ins give your real number.
BMR calculator
Your resting burn from four formulas, side by side.
Your protein
Your typical range, and the line under which it is too low.
Your personalized guide
Your maintenance, your target to lose, your date, your protein and the four-week check.
Track it in Gyroscope
Your meals, weigh-ins and steps, and the calorie burn they show.
