How to calculate resting metabolic rate for females?

December 8, 2025 •

4 min read

RMR accounts for approximately 60-70% of an individual's total daily energy expenditure, representing the calories burned at rest to sustain basic life functions. Understanding this baseline is crucial for effectively managing body weight and health goals. Knowing your RMR provides a personalized caloric benchmark to guide your diet and exercise plan.

Quick Summary

This guide provides step-by-step instructions on how to calculate resting metabolic rate for females using the Mifflin-St Jeor and Harris-Benedict formulas. It covers necessary variables, explains the difference between RMR and BMR, and offers tips to increase metabolic rate.

Key Points

Mifflin-St Jeor Formula: Use the equation $RMR = (10 \times \text{weight kg}) + (6.25 \times \text{height cm}) - (5 \times \text{age yrs}) - 161$ for an accurate estimate of female RMR.
RMR vs. BMR: RMR is the energy burned at rest, a more practical measure than BMR, and is typically 10-20% higher.
Lean Muscle Matters: Muscle tissue is metabolically more active than fat, so building and maintaining muscle mass directly increases your RMR.
Multiply by Activity Factor: To find your Total Daily Energy Expenditure (TDEE), multiply your RMR by an activity factor (e.g., sedentary 1.2, active 1.55).
Protein and Hydration: Consuming more protein and staying well-hydrated boosts metabolism by increasing the thermic effect of food and supporting calorie-burning processes.
Strength Training is Key: Lifting weights is crucial for maintaining or increasing RMR, as it builds muscle mass, which burns more calories at rest than fat tissue.
Sleep Affects Metabolism: Inadequate sleep can negatively impact hormones that regulate appetite and metabolism, leading to potential weight gain and a slower RMR.

Understanding Resting Metabolic Rate (RMR)

Before you calculate resting metabolic rate for females, it's essential to understand what it is and how it differs from Basal Metabolic Rate (BMR). RMR, also known as Resting Energy Expenditure (REE), is the total number of calories your body burns at rest to maintain essential functions, including breathing, circulating blood, and body temperature regulation. The key distinction is that BMR is measured under very strict, clinical conditions, often after a 12-hour fast and 8 hours of sleep in a thermoneutral environment. RMR, while similar, is a less restrictive measurement that reflects the body's energy expenditure in a normal, resting state and is generally about 10-20% higher than BMR. This makes RMR a more practical and applicable measure for most people tracking their daily caloric needs.

The Most Common Formulas for Female RMR

There are several equations used to estimate RMR, but the most widely accepted and accurate for modern populations are the Mifflin-St Jeor and the revised Harris-Benedict equations. Both rely on a woman's weight, height, and age.

Mifflin-St Jeor Equation for Females

This formula is frequently cited as the most accurate predictor of RMR for modern individuals.

Equation: $RMR = (10 \times \text{weight in kg}) + (6.25 \times \text{height in cm}) - (5 \times \text{age in years}) - 161$

Revised Harris-Benedict Equation for Females

This older, but still frequently used, equation was revised in 1984 to be more accurate.

Equation: $RMR = (9.247 \times \text{weight in kg}) + (3.098 \times \text{height in cm}) - (4.330 \times \text{age in years}) + 447.593$

Step-by-Step Calculation Guide

To calculate your RMR, you will need three pieces of information: your weight, height, and age. Follow these steps:

Gather your data. Record your current weight in kilograms and height in centimeters. If you only know your weight in pounds, convert it by dividing by 2.2046. If your height is in inches, multiply by 2.54.
Choose your formula. Decide whether to use the Mifflin-St Jeor or the revised Harris-Benedict equation. The Mifflin-St Jeor is generally preferred for its more contemporary data set.
Plug in the numbers. Insert your converted weight, height, and age into your chosen formula.
Calculate. Solve the equation to get your estimated RMR in calories per day.

Example using Mifflin-St Jeor: For a 35-year-old female who weighs 65 kg and is 165 cm tall: $RMR = (10 \times 65) + (6.25 \times 165) - (5 \times 35) - 161$ $RMR = 650 + 1031.25 - 175 - 161$ $RMR = 1345.25 \text{ calories/day}$

Comparison of RMR Calculation Formulas


Feature	Mifflin-St Jeor Equation	Revised Harris-Benedict Equation
Development Year	1990	Revised 1984
Accuracy	Considered more accurate for modern populations.	Less accurate than Mifflin-St Jeor due to older data.
Equation Variables	Weight (kg), Height (cm), Age (yrs).	Weight (kg), Height (cm), Age (yrs).
Female Subtraction	Subtracts a larger number (-161), accounting for lower average muscle mass in females.	Subtracts a smaller number, based on older data.
Context	Based on contemporary research, which may be more relevant.	Based on older studies, potentially less accurate for today's demographics.

Factors Influencing a Woman's RMR

While equations provide a good estimate, several factors can influence a woman's actual RMR:

Muscle Mass: Muscle tissue is more metabolically active than fat tissue. A woman with a higher percentage of lean body mass will have a higher RMR.
Age: As women age, especially after 20, RMR gradually declines, partly due to a natural loss of muscle mass.
Hormones: Hormonal fluctuations, such as those during the menstrual cycle, pregnancy, and menopause, can affect RMR. For example, pregnancy increases RMR.
Genetics: Genetic factors play a role in determining your inherent metabolic rate.
Body Composition: The ratio of muscle to fat is the most significant factor affecting RMR.

Using Your RMR for Health Goals

Once you have your RMR, you can calculate your Total Daily Energy Expenditure (TDEE) by multiplying your RMR by an activity factor. This TDEE is the total calories you burn in a day, including physical activity. To lose weight, you need to consume fewer calories than your TDEE (create a calorie deficit). Conversely, to gain weight, you would need to consume more calories. For personalized advice, consider consulting a healthcare provider or a registered dietitian.

To boost your metabolism, focus on consistent lifestyle habits. Incorporate strength training to build and maintain muscle mass. Ensure a high-protein diet, as it requires more energy to digest than fats or carbs. Staying hydrated is also key, as even mild dehydration can slow your metabolism. Consistent, quality sleep helps regulate appetite-controlling hormones and supports overall metabolic health.

For more detailed information on metabolic health, explore resources from authoritative sources, such as the National Institutes of Health.

Conclusion

Calculating your resting metabolic rate is a valuable first step toward personalized weight management and fitness goals. By using modern formulas like the Mifflin-St Jeor equation, women can get an accurate estimate of their baseline calorie needs. Understanding the factors that influence RMR, such as muscle mass and age, empowers you to make informed decisions about diet and exercise. By combining this knowledge with a consistent routine of strength training, proper nutrition, hydration, and quality sleep, you can effectively optimize your metabolism and achieve your desired health outcomes.

Frequently Asked Questions

The Mifflin-St Jeor formula is generally considered the most accurate predictor of resting metabolic rate for modern adult populations.

To lose weight, you must consume fewer calories than your total daily energy expenditure (TDEE). First, calculate your RMR, then multiply it by an activity factor to get your TDEE, and finally, consume slightly fewer calories than that number.

RMR is the energy burned during a typical resting state, while BMR is measured under stricter laboratory conditions (after fasting and a full night's sleep). RMR is a more accessible and practical metric for most people.

Yes, RMR naturally declines with age, largely due to a decrease in lean muscle mass. However, consistent strength training can help mitigate this decline.

Yes, muscle tissue is more metabolically active than fat. Therefore, increasing your muscle mass through strength training will increase your RMR, helping you burn more calories at rest.

Hormones like estrogen and thyroid hormones play a significant role in regulating metabolism. Fluctuations during the menstrual cycle, pregnancy, or menopause can affect a woman's RMR.

Yes. Severe calorie restriction can cause your body to slow down its metabolism to conserve energy. Eating a balanced, nutrient-dense diet with enough protein helps maintain a healthy metabolic rate.