Humans burn calories every day just by being alive and through normal bodily functions and activities. The number of calories burned depends on many factors like age, sex, body size and composition. On average, adult males burn around 2,500 calories per day and adult females burn around 2,000 calories per day without any exercise. However, this can vary significantly from person to person.
What are calories?
Calories are a unit of energy. The calories in food provide the energy your body needs to function and be active. The more active you are, the more calories you burn. When you consume more calories than you burn, the excess calories are stored as fat. When you burn more calories than you consume, you lose weight by tapping into fat stores for energy.
What affects how many calories you burn?
Several factors affect how many calories you naturally burn each day without physical activity:
- Age – Metabolism slows down as you get older, so the number of calories burned at rest decreases with age.
- Sex – Men naturally have more muscle mass and less body fat than women, so they burn more calories at rest.
- Body size – The bigger you are, the more calories you burn. Taller and heavier people need more energy just to sustain basic body functions.
- Body composition – Muscle burns more calories than fat, so the more muscle mass you have, the more calories you burn.
- Pregnancy and breastfeeding – Energy needs increase during pregnancy and breastfeeding.
- Genetics – Some people inherit a faster metabolism than others.
- Environmental temperature – Your body burns more calories to maintain body temperature in cold environments.
Basal Metabolic Rate (BMR)
Your basal metabolic rate (BMR) is the minimum number of calories your body needs to perform essential functions like breathing, blood circulation, and organ function. It makes up the largest portion of your daily calorie burn. BMR is strongly linked to your total body size and composition. Men naturally have a higher BMR than women.
On average, adult BMR values are:
- Women: 1,200 to 1,600 calories per day
- Men: 1,500 to 2,000 calories per day
BMR declines with age as metabolism slows and muscle mass decreases. A 20 year old may burn 300 more calories per day than a 70 year old, even without exercise.
Calculating your BMR
You can estimate your BMR using the following formulas:
For men:
BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)
For women:
BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)
Calories burned from daily activities
In addition to your BMR, you burn calories through daily activities like walking, having a shower, getting dressed, cooking, shopping and even just fidgeting. This is known as your non-exercise activity thermogenesis (NEAT).
NEAT accounts for about 15-50% of total calorie expenditure for sedentary to moderately active people. For typical office workers, NEAT may burn 300 to 800 calories per day on top of BMR.
Calories burned by common daily activities:
| Activity | Calories burned per hour (for 150 lb person) |
|---|---|
| Cooking or food prep | 100 |
| Showering | 100 |
| Getting dressed | 70 |
| Walking around the house | 200 |
| Light house cleaning | 220 |
| Grocery shopping | 180 |
| Desk work | 80 |
Fidgeting and spontaneous muscle contractions can burn up to 350 extra calories per day. Standing can burn 100 more calories per hour than sitting.
Calories burned through physical activity and exercise
The more active you are, the more calories you burn above your BMR and NEAT. Physical activity like sports, exercise and intense work will have the biggest impact on your energy expenditure.
Here are estimates for calories burned per hour of exercise for a 150 lb person:
| Activity | Calories burned per hour |
|---|---|
| Walking (3 mph) | 240 |
| Light cycling (10 mph) | 290 |
| Moderate cycling (12-13.9 mph) | 590 |
| Jogging (5 mph) | 550 |
| High-impact aerobics | 480 |
| Running stairs | 950 |
| Swimming laps | 510 |
| Weight lifting | 220 |
As intensity increases, the number of calories burned will also increase. For example, running at 5 mph burns more calories per hour than walking at 3 mph.
How to burn more calories every day
Here are some tips to increase your calorie burn each day:
- Increase general daily movement like walking, standing, cleaning and taking the stairs.
- Do yardwork and housework at a vigorous pace like vacuuming briskly.
- Fidget, tap your feet and contract muscles periodically when seated.
- Set alarms to get up and walk around every 30-60 minutes if you have a desk job.
- Exercise regularly – aim for 150 minutes of moderate activity or 75 minutes of vigorous activity per week.
- Strength train to build muscle mass – muscles burn more calories than fat.
- Drink cold water – your body burns calories to warm it to body temperature.
How many calories should you consume daily?
The number of calories you should eat each day depends on your age, sex, activity level and whether you want to lose, gain or maintain your weight.
As a rough guide:
- Sedentary adult women need around 1,600 – 2,400 calories.
- Sedentary adult men need around 2,000 – 3,000 calories
You need to consume fewer calories than you burn to lose weight, or more calories than you burn to gain weight. To sustain current weight, calories in should equal calories out.
Estimating your calorie needs
Use this simple formula to estimate your calorie needs for weight maintenance:
Women: BMR x 1.2-1.4 (activity factor)
Men: BMR x 1.3-1.5 (activity factor)
So for a sedentary woman with a BMR of 1400 calories, estimated needs are:
1400 x 1.2 = 1680 calories per day
And for a moderately active man with a BMR of 1800 calories, estimated needs are:
1800 x 1.4 = 2520 calories per day
The bottom line
On average, adult women burn around 2,000 calories per day, and adult men burn around 2,500 calories per day without any exercise. However, calorie needs can vary significantly based on age, body size and composition, sex, genetics, and activity level.
To lose weight, you need to burn more calories than you consume. To gain weight, consume more calories than you burn. For weight maintenance, balance your physical activity and calorie intake to achieve energy balance.
