Calories Burned at Rest Calculator

Enter your weight, height, age, gender, and sedentary hours to calculate how many calories you burn at rest, your BMR, and your remaining daily calorie budget.

Created by Luis GonzalezLast updated: May 18, 2026

How to Use This Calculator

1
Enter your current body weight
Input your weight in pounds. This is a primary factor in determining your resting metabolic rate.
2
Provide your height in inches
Enter your height in inches. For example, 5 feet 8 inches would be 68 inches.
3
Specify your age in years
Input your age. Basal Metabolic Rate (BMR) naturally decreases with age.
4
Input hours at rest
Enter the number of sedentary hours you wish to calculate for, such as 8 hours for sleep.
5
Select your gender
Choose 'Male' or 'Female' as the Mifflin-St Jeor equation uses different factors for each.
6
Review your results
The calculator will display your total calories burned at rest for the specified period, along with your BMR and other metrics.

Example Calculation

A 30-year-old male, 5'10" (70 inches) tall and weighing 170 lbs, wants to know his calorie burn during an 8-hour sleep.

Weight (lbs)

170

Height (in)

Age (yrs)

Hours at Rest (hrs)

Gender

male

Results

579 cal

Tips

Compare to your BMR

Your BMR is the total calories burned over 24 hours at absolute rest. If your 'Hours at Rest' is less than 24, compare your result to the full 24-hour BMR to understand the proportion of your daily resting energy expenditure.

Adjust for activity levels

The BMR calculation is for absolute rest. To estimate your total daily energy expenditure (TDEE), multiply your BMR by an activity factor (e.g., 1.2 for sedentary, 1.375 for lightly active). Remember that a 500-calorie daily deficit typically leads to about one pound of fat loss per week.

Consider age-related changes

BMR generally declines by about 1-2% per decade after age 20. If you're over 40, regularly re-evaluate your BMR to ensure your calorie targets remain accurate for weight management in 2025.

Estimating Your Resting Calorie Expenditure

The Calories Burned at Rest Calculator provides an estimate of the energy your body expends purely on essential functions, like breathing, circulation, and cell production, over a specified period. This tool leverages the Mifflin-St Jeor equation, widely recognized for its accuracy, to help individuals understand their basal metabolic rate (BMR) and how many calories are burned when completely sedentary. For an average adult, this baseline burn can account for 60-75% of total daily energy expenditure, often ranging from 1,400 to over 2,000 calories per 24-hour period.

Understanding Your Basal Metabolic Rate in Fitness

Your Basal Metabolic Rate (BMR) is the fundamental number in any calorie-tracking or weight management plan. It represents the minimum energy required to keep your body functioning at rest, without any physical activity. Knowing your BMR is crucial because it sets the baseline for your daily caloric needs; any calories consumed beyond this amount must fuel activity or will be stored. For someone aiming for weight loss, maintaining a consistent deficit of 500 calories per day below their total daily energy expenditure (TDEE) — which includes BMR plus activity — is a common target to lose about one pound per week.

The Mifflin-St Jeor Formula for BMR

The Calories Burned at Rest Calculator uses the Mifflin-St Jeor equation, one of the most accurate formulas developed in 1990 for estimating BMR. This formula accounts for sex, weight, height, and age to provide a personalized metabolic baseline. It is preferred by many health professionals over older equations, such as the Harris-Benedict, due to its improved predictive accuracy across diverse populations.

The formula is as follows:

For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5
For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161

Once the BMR is calculated, the total calories burned at rest for a specific number of hours is simply:

Calories Burned at Rest = (BMR / 24) × Hours at Rest

💡 If your goal is weight management, understanding your BMR is the first step; our Fat Loss Rate Calculator can then help you project how quickly you can achieve your goals.

Calculating Resting Calories for a 30-Year-Old

Let's consider a scenario where a 30-year-old male, standing 5 feet 10 inches (70 inches) tall and weighing 170 pounds, wants to determine how many calories he burns during an 8-hour sleep period.

Convert weight and height:
- Weight: 170 lbs × 0.453592 kg/lb = 77.11 kg
- Height: 70 inches × 2.54 cm/inch = 177.8 cm
Calculate Basal Metabolic Rate (BMR) for a male:
- BMR = (10 × 77.11) + (6.25 × 177.8) - (5 × 30) + 5
- BMR = 771.1 + 1111.25 - 150 + 5
- BMR = 1737.35 calories/day
Calculate calories burned over 8 hours:
- Calories per hour = 1737.35 / 24 = 72.39 calories/hour
- Calories burned over 8 hours = 72.39 calories/hour × 8 hours = 579.12 calories

Therefore, this individual burns approximately 579 calories during an 8-hour period of rest.

💡 While the Mifflin-St Jeor equation is robust, if you're also tracking athletic performance, our Fantasy Sports Total Points Calculator offers a different kind of performance metric for recreational analysis.

Optimizing Your Basal Metabolic Rate for Health

Your Basal Metabolic Rate (BMR) isn't just a static number; it's a dynamic indicator of your body's fundamental energy demands. Factors like muscle mass significantly influence BMR, with more muscle leading to a higher resting calorie burn. For example, strength training can increase your BMR by 5-10% over time, making weight management easier. Conversely, a prolonged caloric deficit can sometimes lower BMR, a phenomenon known as metabolic adaptation. Focusing on adequate protein intake (e.g., 0.7-1.0 grams per pound of body weight) and consistent resistance training can help maintain or even increase your BMR, supporting overall metabolic health and making it easier to manage body weight long-term.

The Mifflin-St Jeor Equation: A Modern BMR Standard

The Mifflin-St Jeor equation, published in 1990, emerged from a study that aimed to develop a more accurate predictive equation for Basal Metabolic Rate (BMR). It was designed to address limitations in older formulas, like the Harris-Benedict equation (1919), which often overestimated BMR in modern, less active populations. The research, conducted by Mifflin, St Jeor, et al., at the University of Nevada, Reno, analyzed resting energy expenditure data from a diverse group of subjects using indirect calorimetry. Their findings led to the refined coefficients used today, making it a cornerstone in clinical and dietary settings for its improved precision, particularly for individuals who are overweight or obese, where older formulas struggled to provide reliable estimates.

Frequently Asked Questions

What is the difference between BMR and RMR?

Basal Metabolic Rate (BMR) measures the minimum calories your body needs to perform basic, life-sustaining functions at complete rest in a fasted state. Resting Metabolic Rate (RMR) is similar but less restrictive, measuring calories burned at rest after a period of relaxation, not necessarily fasting. RMR is typically easier to measure and often used interchangeably with BMR, though BMR is usually slightly lower.

How does the Mifflin-St Jeor equation compare to other BMR formulas?

The Mifflin-St Jeor equation is one of the most widely used and considered highly accurate for estimating Basal Metabolic Rate (BMR) in healthy adults, particularly when compared to older formulas like Harris-Benedict. It was developed in 1990 and tends to be more precise for a broader population, showing a predictive accuracy within 10% for about 82% of individuals.

Why does gender affect calorie burn at rest?

Gender affects calorie burn at rest primarily due to differences in body composition. Males typically have a higher percentage of muscle mass and lower body fat percentage compared to females. Muscle tissue is more metabolically active than fat tissue, meaning it burns more calories even at rest, leading to generally higher BMRs for men.

Can BMR change over time?

Yes, Basal Metabolic Rate (BMR) can change over time due to several factors. Age is a significant factor, with BMR generally decreasing by 1-2% per decade after early adulthood. Changes in body composition, such as gaining muscle mass (which increases BMR) or losing fat, also affect it. Hormonal fluctuations, illness, and even environmental temperature can also cause temporary shifts.

What is a typical BMR for an adult?

A typical Basal Metabolic Rate (BMR) for an adult can vary widely but generally falls between 1,400 to 2,000 calories per day. For instance, a 30-year-old male weighing 170 lbs might have a BMR around 1,700-1,800 calories, while a 30-year-old female weighing 130 lbs might have a BMR closer to 1,300-1,400 calories. These are baseline energy needs before any physical activity.