What are my RMR calories? A Guide to Calculating Your Resting Metabolic Rate

November 2, 2025 •

3 min read

Approximately 60-75% of your total daily energy expenditure is composed of your Resting Metabolic Rate (RMR). This baseline measurement is the energy your body needs to perform vital functions like breathing, circulation, and cell production, even while at rest. Understanding precisely what are my RMR calories? is the foundational first step toward creating a personalized and effective nutrition diet and fitness plan.

Quick Summary

This guide explains what RMR is, provides methods for estimating your RMR calories, and details how to use this information to set effective and personalized nutritional goals.

Key Points

RMR is Your Baseline Energy: It is the number of calories your body burns at rest to perform essential life-sustaining functions, forming the foundation of your daily energy needs.
Formulas Provide Accurate Estimates: Equations like Mifflin-St Jeor and Katch-McArdle can be used at home to get a reliable estimate of your RMR without expensive lab testing.
RMR is Influenced by Many Factors: Your age, gender, genetics, body composition (muscle vs. fat), and sleep quality all play a role in determining your RMR.
Lifestyle Changes Can Affect RMR: Building muscle through strength training is a key way to increase your RMR, as muscle tissue burns more calories at rest than fat.
RMR is Key for Calorie Planning: Using your RMR and activity level to calculate your Total Daily Energy Expenditure (TDEE) allows for personalized and effective strategies for weight loss, maintenance, or gain.
Avoid Extreme Caloric Restriction: Eating too few calories for an extended period can slow your metabolism, so it is important to create a moderate deficit based on your RMR for safe weight loss.

What is Resting Metabolic Rate (RMR)?

Resting Metabolic Rate, or RMR, is the number of calories your body burns at rest to maintain essential functions such as maintaining your heartbeat, breathing, blood circulation, organ function, and cell production. Unlike Basal Metabolic Rate (BMR), which requires strict lab conditions, RMR is a more accessible estimate measured in a relaxed state. While often used interchangeably, RMR is typically slightly higher than BMR due to less stringent resting requirements. RMR is a key part of your Total Daily Energy Expenditure (TDEE), representing your baseline energy needs before accounting for digestion and activity.

How to Calculate Your RMR Calories

While indirect calorimetry is the most accurate method, it requires specialized equipment. You can estimate your RMR at home using several common formulas that require your weight, height, and age. The Katch-McArdle formula also requires your lean body mass.

The Mifflin-St Jeor Equation

This is a widely used and accurate equation for estimating RMR.

For Males: RMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
For Females: RMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

The Harris-Benedict Equation

The revised Harris-Benedict equation is more reliable than the original version.

For Males (Revised): RMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age in years)
For Females (Revised): RMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) - (4.330 x age in years)

The Katch-McArdle Formula

This formula is useful if you know your Lean Body Mass (LBM).

For both sexes: RMR = 370 + (21.6 x LBM in kg)

Factors That Influence Your RMR

Your RMR is affected by several factors, some you can control and some you cannot.

Uncontrollable Factors

Age: RMR decreases with age due to muscle mass decline.
Gender: Men typically have a higher RMR than women of similar age and weight due to generally having more muscle.
Genetics: Your genetic makeup influences how your body burns calories.
Hormonal Health: Conditions like hypothyroidism can slow metabolism.

Controllable Factors

Body Composition: Muscle is more metabolically active than fat, so increasing muscle mass can raise RMR.
Dietary Habits: Severe calorie restriction can lower RMR, while regular, nutritious meals support a healthy metabolic rate.
Physical Activity: Regular exercise, particularly strength training, builds muscle and can increase RMR.
Sleep Quality: Poor sleep can disrupt hormones that regulate metabolism, potentially slowing RMR.
Hydration: Staying hydrated is important for metabolic processes.

RMR Calculation Methods: A Comparative Look


Method	Variables Used	Accuracy	Cost/Accessibility	Application
Indirect Calorimetry	Oxygen and CO2 exchange	Highest (Gold Standard)	High Cost / Low Accessibility (Clinical Setting)	Clinical diagnosis, highly accurate personalized planning
Mifflin-St Jeor Equation	Weight, height, age, sex	High (Best for most people)	Free / High Accessibility (Online Calculators)	General population for estimating caloric needs
Harris-Benedict Equation	Weight, height, age, sex	Moderate (Older, tends to overestimate)	Free / High Accessibility (Online Calculators)	Historically popular, useful with modern revisions
Katch-McArdle Formula	Lean Body Mass	High (Requires LBM)	Free / Moderate Accessibility (Needs body composition measurement)	Athletes and individuals with measured body composition

Using Your RMR to Achieve Nutritional Goals

Your RMR is the starting point for calculating your Total Daily Energy Expenditure (TDEE), which helps in setting calorie goals for weight management.

Step-by-Step for Creating a Plan

Calculate Your RMR: Use a suitable formula like Mifflin-St Jeor.
Determine Your Activity Level: Choose the multiplier that matches your activity level.
- Sedentary: RMR x 1.2
- Lightly Active: RMR x 1.375
- Moderately Active: RMR x 1.55
- Very Active: RMR x 1.725
- Extremely Active: RMR x 1.9
Calculate Your TDEE: Multiply your RMR by your activity multiplier.
Set Your Caloric Target: Adjust your TDEE based on your goal.
- Weight Loss: Consume 500-1000 fewer calories than your TDEE, staying above your RMR.
- Weight Maintenance: Match your intake to your TDEE.
- Weight Gain: Consume a moderate surplus above your TDEE.

Conclusion: The First Step to a Personalized Diet

Knowing "What are my RMR calories?" is crucial for creating a personalized nutrition and fitness plan. It allows you to move away from general advice and tailor your caloric intake to your body's specific needs for weight loss, maintenance, or gain. While formulas provide good estimates, remember that RMR can change, particularly with changes in body composition or during significant weight loss. Regularly monitoring and adjusting your plan is vital for long-term success. For the most accurate measurement, consider consulting a professional for an indirect calorimetry test.

Source Link: The Cleveland Clinic offers a detailed explanation of BMR and RMR calculation methods.

Frequently Asked Questions

RMR (Resting Metabolic Rate) and BMR (Basal Metabolic Rate) both measure calories burned at rest. However, BMR is measured under stricter conditions (complete rest, fasted state), while RMR is measured under more relaxed resting conditions. For practical purposes, RMR is a more accessible and realistic estimate of your baseline caloric needs.

The Mifflin-St Jeor equation is widely considered one of the most accurate formulas for estimating RMR in the general population. For individuals with a known lean body mass, the Katch-McArdle formula can offer a more precise result.

You can increase your RMR by building muscle mass through regular strength training, as muscle tissue is more metabolically active than fat. Staying active, eating adequate protein, getting enough sleep, and staying hydrated also help support a healthy metabolism.

RMR typically decreases with age due to a natural decline in muscle mass. As people get older, their muscle mass tends to decrease while their body fat percentage increases, resulting in a slower metabolic rate.

Your RMR provides the baseline number of calories your body needs. By calculating your Total Daily Energy Expenditure (TDEE) and consuming slightly fewer calories than that amount, you can create a controlled and sustainable calorie deficit necessary for weight loss.

RMR is influenced by various factors including body composition. A lower RMR than average could indicate lower muscle mass or other factors like hormonal health. Instead of comparing to others, use your personalized RMR as a baseline for your own journey.

Yes, indirect calorimetry, which measures oxygen consumption, is the most precise method for measuring RMR. While formulas are excellent estimation tools, a professional test provides the most accurate data for truly personalized planning.