Press ESC to close

Resting Metabolic Rate Calculator

Estimate your resting metabolic rate to better understand your baseline energy needs and metabolic health

Resting Metabolic Rate Calculator

Your resting metabolic rate (RMR) represents the number of calories your body burns at rest to maintain essential physiological functions such as breathing, circulation, temperature regulation, and cellular repair. Knowing your resting metabolic rate is fundamental for managing body weight, designing nutrition plans, and optimizing long-term metabolic health.

A resting metabolic rate calculator provides an evidence-based estimate of how much energy your body requires daily without accounting for physical activity. This baseline value becomes the foundation for calculating total daily energy expenditure and making informed dietary adjustments.

Resting Metabolic Rate (RMR) Calculator

Estimate the calories your body burns at rest — including food digestion via the Thermic Effect of Food (TEF). Based on the Harris–Benedict equation (1919, revised 1984).

Your Profile (Step 1 of 3)
⚙

Your Profile

RMR is calculated from your biological sex, age, height, and weight using the Harris–Benedict equation. Unlike BMR, RMR includes the energy cost of food digestion (Thermic Effect of Food).

♂
Male
♀
Female
Valid range: 18–120 years.
Please enter an age between 18 and 120.
Please enter a height between 100 and 250 cm.
Please enter a weight between 20 and 500 kg.
--
BMR (kcal/day)
--
RMR preview (kcal/day)
🍽

Thermic Effect of Food (TEF)

RMR differs from BMR in that it accounts for the energy your body spends digesting, absorbing, and storing nutrients — the Thermic Effect of Food. This typically adds 5–10% on top of BMR (Kinabo & Durnin, Br J Nutr, 1990).

5%
Low
High fat diet, less digestion effort
7.5%
Average
Mixed balanced diet (recommended)
10%
High
High protein or high carb diet
TEF range 5–10% per Kinabo & Durnin (1990) and McMurray et al., Med Sci Sports Exerc (2014). Protein has the highest TEF (20–30%), carbohydrates 5–10%, fats 0–3%.

Resting Metabolic Rate (RMR)

--
kcal / day
--
--
Sex
--
Age
--
Height
--
Weight

Underlying BMR (before TEF)

--
kcal / day
Harris–Benedict equation — energy at complete physiological rest

BMR

--
kcal / day

TEF calories

--
kcal / day

RMR

--
kcal / day

RMR vs BMR

--
extra kcal from TEF

Calorie breakdown: BMR vs. TEF

BMR
TEF
BMR: -- kcal
TEF: -- kcal

Step-by-step calculation

Equation: --
BMR formula: --
BMR result: --
TEF: BMR × TEF% = --
RMR = BMR + TEF: --

Thermic Effect of Food by macronutrient

Macronutrient TEF range Mechanism Source
Protein 20–30% Highest digestion cost; amino acid processing, gluconeogenesis Westerterp, Nutr Metab (2004)
Carbohydrates 5–10% Glycogen synthesis and glucose metabolism Kinabo & Durnin, Br J Nutr (1990)
Fat 0–3% Lowest cost; fatty acids easily incorporated into adipose tissue Westerterp, Nutr Metab (2004)
Mixed diet (overall) 5–10% Typical Western mixed-macronutrient diet average McMurray et al., Med Sci Sports Exerc (2014)

Factors that affect your RMR

Factor Direction Explanation
Muscle mass ↑ Increases RMR Muscle tissue burns ~6× more calories at rest than fat; resistance training is the most effective way to raise RMR (McMurray et al., 2014)
Age ↓ Decreases RMR RMR falls 1–2% per decade after age 20, primarily due to loss of lean mass (Harris & Benedict, 1919)
Body size ↑ Increases RMR Larger body = more cells requiring energy. Accounts for ~60–70% of RMR variance (Livingston & Kohlstadt, Obes Res, 2005)
Genetics Variable Up to 26% of unexplained RMR variance is genetic (Johnstone et al., Am J Clin Nutr, 2005)
Cold environment ↑ Increases RMR Thermogenesis increases metabolic rate to maintain core body temperature
Regular meals ↑ Increases RMR Frequent eating sustains TEF activity throughout the day
Crash dieting ↓ Decreases RMR Severe caloric restriction triggers adaptive thermogenesis, reducing RMR by up to 15% (McMurray et al., 2014)
Pregnancy ↑ Increases RMR Higher metabolic demand to support fetal growth and increased maternal tissue

BMR vs. RMR — key differences

Parameter BMR RMR
Full name Basal Metabolic Rate Resting Metabolic Rate
Test conditions Complete physiological rest; 12h fast; 8h sleep; supine in thermoneutral room 15-min relaxation; overnight fast; awake and resting
Includes TEF No — digestive system must be inactive Yes — accounts for ongoing digestion energy
Typical difference Lower by ~5–10% Higher by ~5–10% vs BMR
Practical use Laboratory reference standard Better real-world estimate of daily resting calorie needs
Accuracy (calculator) ±200–300 kcal/day ±200–300 kcal/day + TEF estimate
Source: McMurray et al., Med Sci Sports Exerc (2014); Harris & Benedict, PNAS (1919); Livingston & Kohlstadt, Obes Res (2005).
How to use your RMR Your RMR represents the minimum number of calories your body needs each day while at rest. To lose weight safely, aim to eat slightly above your RMR — your body will draw the deficit from stored energy (fat). Never restrict calories below your RMR without medical supervision, as this can trigger adaptive thermogenesis and muscle loss. Multiply your RMR by your Physical Activity Level (PAL) to estimate Total Daily Energy Expenditure (TDEE).
Medical disclaimer This calculator uses the Harris–Benedict equation (Harris & Benedict, PNAS, 1919; Roza & Shizgal, Am J Clin Nutr, 1984) with a TEF adjustment as described by Kinabo & Durnin (Br J Nutr, 1990). Online RMR estimates carry an accuracy of approximately ±300 kcal/day (Livingston & Kohlstadt, Obes Res, 2005). The most precise RMR measurement requires indirect calorimetry at a licensed clinical facility. This tool does not account for body composition, hormonal status, medications, or individual metabolic variation. Consult a registered dietitian or physician before making significant dietary changes.

Our other tools

Understanding Resting Metabolic Rate Calculator

 

A resting metabolic rate calculator estimates the energy your body expends at rest using validated predictive equations. RMR is closely related to basal metabolic rate (BMR), though RMR is slightly higher because it does not require strict laboratory fasting and testing conditions.

One of the most widely accepted formulas for estimating resting metabolic rate is the Mifflin-St Jeor equation:

For men:
RMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5

For women:
RMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

This equation accounts for body size, age, and sex — key determinants of metabolic rate. Individuals with greater lean body mass generally have a higher resting metabolic rate because muscle tissue requires more energy than fat tissue.

While a resting metabolic rate calculator provides a reliable starting point, actual energy expenditure can vary due to genetics, hormonal status, sleep quality, stress levels, medications, and metabolic adaptation. For the most accurate measurement, indirect calorimetry in a clinical setting remains the gold standard.

On the same subject

Longevity Tools
  • 16 Mar 2026
Fat Calculator: Accurately Estimate Your Body Fat Percentage

Understanding your body fat percentage…

Longevity Tools
  • 16 Mar 2026
Net Carb Calculator: Easily Track Your Carbohydrate Intake

Managing carbohydrates is key for…

Longevity Tools
  • 16 Mar 2026
Future Height Calculator: Estimate Your Adult Height Accurately

Wondering how tall you—or your…

Stay Informed

 Stay informed with clear, science-backed insights on longevity, nutrition and preventive health. Each week, Sogevity shares practical tools, research highlights and simple habits to help you extend your healthspan and make smarter decisions for your future.

    FAQ

    Understanding this calculator can raise questions. Here you’ll find clear, evidence-based answers to help you interpret your results and understand the science behind it.

    Basal metabolic rate (BMR) is measured under strict laboratory conditions after fasting and complete rest. Resting metabolic rate is measured under less controlled conditions and is typically 5–10% higher. In practical use, both values are often used interchangeably in predictive equations.

    Predictive equations are generally accurate within 5–15% for most individuals. However, accuracy may decrease in people with very high muscle mass, obesity, or metabolic disorders. Tracking weight stability over time helps validate your estimated value.

    Yes. Resting metabolic rate gradually declines with age, primarily due to reductions in lean muscle mass and hormonal changes. Strength training and adequate protein intake can help mitigate this decline.

    Yes. Chronic sleep deprivation and high stress can influence hormonal balance, potentially affecting energy expenditure. While these factors may not dramatically change RMR, they can impact total daily energy expenditure and metabolic efficiency.

    Using a resting metabolic rate calculator allows you to estimate your body’s baseline energy needs with scientific precision. This value forms the cornerstone of any effective nutrition or weight management strategy.

    By understanding your resting metabolic rate, you gain insight into how your body utilizes energy at rest — a critical factor in long-term metabolic health, body composition, and longevity. Regular reassessment ensures your nutrition remains aligned with your evolving physiology.