The average woman burns roughly 2,000 calories per day, and the average man burns about 2,500, according to NHS guidelines. But those are broad estimates. Your actual number depends on your body size, age, how much muscle you carry, and how much you move throughout the day. The real range spans from under 1,500 for a small, sedentary older adult to well over 3,500 for a large, physically active person.
The Three Components of Your Daily Burn
Your body burns calories through three distinct channels, and understanding the split helps explain why two people of the same weight can have very different daily totals.
Basal metabolic rate (BMR) accounts for about 70% of your total daily burn. This is the energy your body uses just to stay alive: pumping blood, breathing, maintaining body temperature, replacing cells. Even if you stayed in bed all day, this baseline cost would still be substantial.
Physical activity makes up roughly 20% on average but is the most variable component. This includes deliberate exercise and also all the smaller movements you make throughout the day, like walking to your car, fidgeting, or standing while cooking. The difference in calories burned through daily movement can reach up to 2,000 calories between two people of similar size, depending largely on occupation and lifestyle. People with sedentary desk jobs burn about 140 fewer calories per day through work activities than workers did in 1960.
The thermic effect of food covers the remaining 10%. Digesting food itself costs energy, but the amount varies by what you eat. Protein is the most metabolically expensive to process, raising your metabolic rate by 15 to 30% of the calories consumed. Carbohydrates cost 5 to 10%, and fats cost almost nothing at 0 to 3%. This is one reason high-protein diets slightly increase total calorie burn.
How to Estimate Your Number
The most widely recommended formula for estimating your resting metabolic rate is the Mifflin-St Jeor equation. The Academy of Nutrition and Dietetics considers it the most accurate option when you can’t get your metabolism measured directly. It predicted resting metabolic rate within 10% of the true value for 70% of people tested, which is meaningfully better than the older Harris-Benedict equation (accurate within 10% for only 39 to 64% of people).
The Mifflin-St Jeor formula works like this:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (4.92 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (4.92 × age) − 161
For a 35-year-old woman who is 5’5″ (165 cm) and weighs 150 pounds (68 kg), the math comes out to roughly 1,380 calories per day at rest. For a 35-year-old man who is 5’10” (178 cm) and weighs 180 pounds (82 kg), the resting figure lands around 1,770 calories.
To get your total daily burn, you multiply that resting number by an activity factor. Someone who is sedentary (desk job, no regular exercise) multiplies by about 1.2. Light exercise one to three days a week bumps it to around 1.375. Moderate exercise three to five days per week uses roughly 1.55. Working out six to seven days a week pushes it to about 1.725, and intense daily training goes up to 1.9.
Using our example, the 35-year-old woman with a resting rate of 1,380 would burn about 1,650 calories on a sedentary day and roughly 2,140 if she exercises moderately most days of the week.
Why Muscle Mass Matters
A pound of muscle burns approximately 4.5 to 7 calories per day at rest. That sounds modest, but it adds up. Someone who carries 20 extra pounds of muscle compared to someone of the same weight with more body fat could burn 90 to 140 additional calories daily before doing anything active. Over a year, that difference alone accounts for roughly 10 to 15 pounds of caloric expenditure.
Your internal organs actually burn far more calories per pound than muscle does, at rates 15 to 40 times higher than muscle tissue. But you can’t grow a bigger liver through exercise. Muscle is the only metabolically active tissue you can meaningfully increase, which is why strength training is consistently linked to higher resting metabolic rates.
How Age Affects Your Burn
A landmark study published in Science tracked energy expenditure across the human lifespan and overturned some long-held assumptions. Metabolism doesn’t start dropping in your 30s or 40s, as many people believe. After adjusting for body size and composition, total daily energy expenditure stays remarkably stable from age 20 all the way to about 60. Men and women showed the same pattern.
The real decline begins around age 60, when both resting and total energy expenditure start falling by about 0.7% per year. By age 90, adjusted total expenditure drops roughly 26% below middle-aged levels. Part of this decline comes from losing muscle mass and overall body weight, but the metabolic slowdown exceeds what the loss of tissue alone would explain. Something about cellular metabolism itself becomes less active in older age.
The practical takeaway: if you’re between 25 and 55 and feel like your metabolism has slowed down, the more likely explanation is that your activity levels or body composition have shifted, not that age has fundamentally changed your metabolic rate.
The Hidden Power of Daily Movement
Structured exercise gets the most attention, but non-exercise activity thermogenesis, or NEAT, often determines more of your daily calorie burn. NEAT includes everything from pacing while on a phone call to taking the stairs, doing housework, or simply standing instead of sitting. The caloric difference between a highly active lifestyle and a sedentary one can reach 2,000 calories per day between people of similar body size.
This explains something that confuses a lot of people: a postal worker who walks all day but never “works out” can easily burn more total calories than an office worker who hits the gym for 45 minutes. A single gym session might burn 200 to 400 calories, but eight hours of walking, standing, and carrying things can burn several times that amount. If you’re trying to increase your daily burn, finding ways to move more throughout the entire day is often more impactful than adding another workout to your week.