Most adults burn between 1,600 and 2,400 calories per day just by existing, and the “right” number to burn depends entirely on your goal. If you want to maintain your current weight, you need to burn roughly what you eat. If you want to lose weight, a deficit of about 500 calories per day is a reliable starting point, which translates to roughly one pound of weight loss per week. The real question isn’t a single magic number. It’s understanding what your body already burns and how to adjust from there.
What Your Body Burns Without Exercise
Your body is burning calories right now, reading this sentence. The largest chunk of your daily calorie burn, somewhere between 45% and 70%, comes from your basal metabolic rate (BMR). That’s the energy your organs, brain, and cells need just to keep you alive: breathing, pumping blood, regulating temperature. You burn these calories whether you move or not.
On top of that, digesting food itself costs energy. Eating a mixed diet increases your metabolic rate by about 10% over the course of the day. So if your BMR is 1,500 calories, digestion adds roughly another 150. The remaining variable is physical activity, which includes both structured exercise and all the movement you do without thinking about it: walking to the kitchen, fidgeting, standing up, carrying groceries. That non-exercise movement alone can vary by as much as 2,000 calories per day between two people of the same size, depending on their job and lifestyle. A mail carrier and an office worker with identical bodies will have dramatically different daily burns.
How to Estimate Your Daily Burn
The most accurate formula for estimating your resting metabolic rate, according to the Academy of Nutrition and Dietetics, is the Mifflin-St. Jeor equation. It uses your weight in kilograms, height in centimeters, and age:
- Men: (9.99 × weight) + (6.25 × height) − (4.92 × age) + 5
- Women: (9.99 × weight) + (6.25 × height) − (4.92 × age) − 161
For a 35-year-old woman who weighs 70 kg (about 154 lbs) and stands 165 cm (5’5″), the math works out to roughly 1,380 calories at rest. For a 35-year-old man at 80 kg (176 lbs) and 178 cm (5’10”), it’s about 1,748 calories. These numbers only reflect what your body burns doing nothing. To get your total daily burn, you multiply by an activity factor: around 1.2 for a sedentary lifestyle, 1.375 for light activity, 1.55 for moderate activity, and 1.725 for very active days. That sedentary woman’s total daily burn would land near 1,650 calories; the moderately active man’s would be closer to 2,700.
How Many Calories to Burn for Weight Loss
A deficit of about 500 calories per day is the most commonly recommended target for steady, sustainable weight loss. You can create that gap by eating less, moving more, or a combination of both. Most people find the combination easier to stick with, since cutting 500 calories purely from food can feel restrictive, and burning 500 calories purely from exercise takes significant effort every single day.
There is a floor you shouldn’t drop below. Women should generally consume at least 1,200 calories per day and men at least 1,500. Going lower than that puts you at risk for nutritional deficiencies and the cascade of problems that follow: fatigue, difficulty concentrating, poor bone density, hormonal disruption, and weakened immunity. In women, consistently undereating relative to activity level can cause irregular or absent periods. In men, it can lower testosterone and reduce bone health. These aren’t just elite-athlete problems. Anyone who combines aggressive calorie restriction with regular exercise can develop them.
How Many Calories Common Activities Burn
Exercise intensity is measured in METs, or metabolic equivalents. A MET of 1.0 is the energy you use sitting still. An activity rated at 7.0 METs burns seven times that amount. To estimate calories, the formula is: METs × your weight in kg × hours. A 70 kg person jogging (7.0 METs) for 30 minutes burns roughly 245 calories. Here’s how common activities compare:
- Brisk walking (3.5 mph): 4.3 METs. A 70 kg person burns about 150 calories in 30 minutes.
- Leisure cycling (10–12 mph): 6.8 METs. About 238 calories per 30 minutes at 70 kg.
- Running (5 mph, 12 min/mile): 8.3 METs. About 290 calories per 30 minutes at 70 kg.
- Running (6 mph, 10 min/mile): 9.8 METs. About 343 calories per 30 minutes at 70 kg.
- Weight training (moderate, 8–15 reps): 3.5 METs. About 123 calories per 30 minutes at 70 kg.
- Vigorous weight training: 6.0 METs. About 210 calories per 30 minutes at 70 kg.
Weight training burns fewer calories in the moment than running, but it builds muscle tissue, which is more metabolically active than fat even at rest. Over time, gaining muscle raises your baseline calorie burn around the clock, not just during workouts.
How Much Exercise You Actually Need
The American Heart Association recommends at least 150 minutes per week of moderate-intensity aerobic activity (like brisk walking or casual cycling), or 75 minutes of vigorous activity (like running), plus two sessions of strength training. That’s the baseline for general health. Bumping up to 300 minutes per week of moderate activity provides additional benefits for weight management and cardiovascular fitness.
Spread across a week, 150 minutes is roughly 22 minutes a day, which for a 70 kg person walking briskly burns about 110 calories per session, or 770 per week. At 300 minutes, you’re looking at around 1,540 extra calories burned weekly from walking alone. Pair that with a modest reduction in food intake, and you’re within range of a 500-calorie daily deficit without any extreme measures.
Age Doesn’t Slow Your Metabolism as Much as You Think
A large-scale study published in Science found that total daily energy expenditure and basal metabolic rate remain stable from age 20 all the way to 60, regardless of sex. That’s a much longer plateau than most people assume. The real decline begins around age 60, when metabolism drops by about 0.7% per year. By age 90, total energy expenditure is roughly 26% lower than in middle-aged adults.
What this means practically: if you’re 40 and feel like your metabolism has tanked, the culprit is more likely reduced activity and lost muscle mass than aging itself. People tend to move less as they get older, sit more at work, and lose muscle if they aren’t actively maintaining it. These are factors you can influence. The age-related metabolic decline that’s truly out of your hands doesn’t kick in until decades later than most people believe.
Putting It All Together
Start by estimating your resting metabolic rate with the Mifflin-St. Jeor equation, then multiply by an activity factor that honestly reflects your daily movement. That gives you a rough total daily burn. If your goal is weight loss, aim for a 500-calorie daily deficit split between eating a bit less and moving a bit more. If your goal is maintenance, match your intake to your estimated burn and adjust based on what the scale does over two to three weeks.
The non-exercise portion of your day matters more than most people realize. Two people with identical gym routines can differ by hundreds of calories simply based on whether they walk or drive, stand or sit, take stairs or elevators. Small increases in daily movement compound over time in ways that a few weekly gym sessions alone cannot replicate. Your calorie burn target isn’t one fixed number. It’s a moving target shaped by your body, your habits, and your goals, and the best approach is to start with a reasonable estimate and let real-world results guide your adjustments.