How many calories do you burn if you rest all day? Understanding your resting metabolism

October 15, 2025 •

4 min read

Your body burns approximately 60% to 70% of your total daily calories simply to keep you alive, even when you are completely at rest. So, how many calories do you burn if you rest all day? The answer lies in understanding your body's essential, behind-the-scenes energy consumption.

Quick Summary

The number of calories your body burns while at rest depends on your individual basal or resting metabolic rate (BMR/RMR). This crucial process is influenced by factors like age, gender, weight, height, and muscle mass, accounting for most of your daily energy use.

Key Points

Resting is a Calorie-Burning Activity: Your body constantly burns calories for vital functions, with 60-70% of daily energy used for basal metabolic needs.
BMR vs. RMR: Basal Metabolic Rate (BMR) is for a perfectly rested state, while Resting Metabolic Rate (RMR) is for an awake, resting state and is a more practical measure.
Factors Influence Your Rate: Age, sex, muscle mass, weight, height, and genetics all play a significant role in determining your individual resting calorie burn.
Major Organs Use Major Energy: The brain and vital organs like the liver and heart consume a large portion of your resting calories.
Non-Exercise Activity Matters: Small movements throughout the day, known as NEAT (Non-Exercise Activity Thermogenesis), can significantly increase your daily calorie expenditure.
You Can Estimate Your BMR: Formulas like the Mifflin-St. Jeor equation provide a useful estimate, though they are not as precise as clinical measurements.
Weight Loss Slows Metabolism: Severe calorie restriction can cause your BMR to slow down as your body tries to conserve energy.

The Science Behind Resting Calorie Burn: BMR vs. RMR

The calories you burn while at rest are a result of your basal metabolic rate (BMR) and resting metabolic rate (RMR). While the terms are often used interchangeably, there is a technical distinction. Your BMR represents the minimum number of calories your body needs to perform life-sustaining functions, such as breathing, blood circulation, and cell production, in a perfectly rested, fasted, and controlled state.

On the other hand, RMR measures the calories burned while at rest but awake, which includes low-effort activities like sitting, fidgeting, and digesting food. Because most people are not in a truly basal state throughout the day, RMR is a more practical and commonly used measure for estimating daily resting energy expenditure. RMR is typically about 10% to 20% higher than BMR.

How Many Calories Do You Burn if You Rest All Day?

Even when you're completely inactive, your body's organs and systems are hard at work. This vital energy consumption accounts for a significant portion of your total daily calorie burn. For an inactive person, the daily calorie burn solely from these basic metabolic processes can range widely, from approximately 1,200 to 2,400 calories.

For example, average daily basal metabolic rates can be estimated by gender and age based on average body sizes in the U.S.:

20-Year-Olds: Around 2,020 calories for males and 1,559 calories for females.
40-Year-Olds: Around 1,907 calories for males and 1,473 calories for females.
60-Year-Olds: Around 1,793 calories for males and 1,386 calories for females.

The Calorie-Consuming Processes of a Resting Body

Brain Function: The brain is a metabolic powerhouse, consuming approximately 20% of the body's energy despite making up only 2% of body mass. It requires a steady energy supply to send electrical signals and process information. While intense thought slightly increases this, the bulk of the energy is for basic functions.
Organ Activity: Vital organs like the heart, liver, and kidneys have extremely high resting metabolic rates, burning hundreds of calories daily to perform their essential roles.
Cellular Maintenance: The body constantly repairs and creates new cells, which requires energy.
Circulation and Respiration: Pumping blood and breathing are involuntary actions that demand a constant energy supply from your body.

Factors That Influence Your Resting Metabolism

Your individual BMR is not static and is affected by several variables that determine your unique resting calorie burn:

Age: BMR generally decreases with age due to muscle mass loss and other physiological changes.
Sex: Men typically have a higher BMR than women, largely because they tend to have more muscle mass.
Body Composition: Muscle tissue is more metabolically active than fat tissue. Therefore, a person with a higher proportion of muscle mass will have a higher BMR than someone with more fat, even at the same weight.
Genetics: Some people are simply predisposed to a faster or slower metabolism due to inherited traits.
Weight and Height: Taller and heavier individuals require more energy to maintain their body functions, resulting in a higher BMR.
Hormones: The thyroid gland plays a crucial role in regulating metabolism. Hormonal imbalances can significantly affect your BMR.
Environmental Temperature: Your body burns more calories to maintain its core temperature in colder environments.

Comparison Table: Resting vs. Low-Effort Activities


Activity	Approximate Calorie Burn (per hour)	Description
Sleeping	40-55 calories	The lowest metabolic rate; body is in full repair mode.
Lying at Rest	50-60 calories	Slightly higher than sleeping, but still very low-energy.
Sitting Upright	60-80 calories	Requires more energy for core stabilization and organ support.
Fidgeting	Up to 350 calories (daily potential)	Small, unconscious movements like tapping your foot can add up.
Light Chores	100-150 calories	Simple household tasks like washing dishes or light cleaning.

Boosting Your Metabolism Without Intense Exercise (NEAT)

Non-Exercise Activity Thermogenesis (NEAT) is the energy expenditure of everything we do that is not sleeping, eating, or sports-like exercise. It can have a significant impact on your daily calorie burn. You can strategically increase your NEAT through small, consistent changes:

Stand More, Sit Less: Use a standing desk or make it a point to stand for a portion of every hour.
Take the Stairs: Opt for stairs over elevators or escalators whenever possible.
Pace While on Calls: Instead of sitting during a phone call, walk around the office or home.
Park Farther Away: A small change, like parking at the far end of the lot, adds extra steps to your day.
Do Your Own Chores: Instead of outsourcing tasks, do them yourself. Cleaning the house or gardening burns calories.

How to Estimate Your Own BMR

To get a personalized estimate of your basal metabolic rate, you can use a formula such as the Mifflin-St. Jeor equation:

For Men: $(10 imes ext{weight in kg}) + (6.25 imes ext{height in cm}) - (5 imes ext{age in years}) + 5$
For Women: $(10 imes ext{weight in kg}) + (6.25 imes ext{height in cm}) - (5 imes ext{age in years}) - 161$

It is important to remember that this formula provides only an estimate, and factors like muscle mass are not fully accounted for. For the most accurate measurement, indirect calorimetry performed in a clinical setting is the gold standard.

Conclusion

Your body's resting metabolism is a complex and highly active process, burning hundreds, or even thousands, of calories every single day just to keep you alive. Understanding the factors that influence your BMR and RMR can be a powerful tool for weight management and overall health awareness. While you can't drastically alter your baseline metabolic rate, simple strategies to boost non-exercise activity can help increase your total daily energy expenditure. The truth is, your body is always working for you—even on a lazy day.

For more information on metabolism and nutrition, you can visit the Cleveland Clinic website.

Frequently Asked Questions

BMR (Basal Metabolic Rate) is the minimum energy required to sustain life in a completely rested, fasted state. RMR (Resting Metabolic Rate) is the energy spent at rest but awake, including minimal activities, and is about 10-20% higher than BMR.

Yes, you can increase your metabolism to some extent. Building more muscle mass is the most effective way, as muscle tissue burns more calories at rest than fat tissue. Staying hydrated and ensuring enough sleep also helps.

While the brain is a major energy consumer, a significant portion is for its baseline function. The energy increase from thinking intensely is minor, unlike the large energy increase in muscles during exercise.

Metabolism slows down with age primarily due to a natural loss of muscle mass. Since muscle is more metabolically active than fat, a reduction in muscle leads to a lower BMR.

Following a very low-calorie diet can cause metabolic adaptation, where your body slows down your BMR to conserve energy in response to the calorie deficit. This can make continued weight loss more difficult over time.

NEAT stands for Non-Exercise Activity Thermogenesis and refers to the calories you burn doing daily activities outside of formal exercise, like fidgeting or walking. You can boost NEAT by taking the stairs, standing more, and doing household chores.

Not necessarily. While a higher-than-average BMR is often associated with higher muscle mass and good health, some studies suggest that an extremely high BMR is linked with higher all-cause mortality. The ideal range seems to be a balanced one.