How to Calculate Your Daily Energy Requirement

November 19, 2025 •

3 min read

The average adult female needs around 1,600-2,400 calories per day, while men need 2,000-3,000, but these are just estimates. To get a more personalized figure, it's crucial to understand how to calculate your daily energy requirement based on individual factors like age, weight, and activity level.

Quick Summary

This guide explains the science behind determining your energy needs, breaking down the calculation of Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). It details the steps for using modern equations and applying activity factors to find a precise caloric intake for your goals.

Key Points

Start with Basal Metabolic Rate (BMR): Your BMR represents the calories your body needs at rest and is the foundation for calculating your total daily energy expenditure (TDEE).
Use the Mifflin-St Jeor Equation for BMR: For the most reliable estimate in healthy adults, use the Mifflin-St Jeor formula, which considers age, sex, weight, and height.
Apply an Activity Factor for TDEE: Multiply your BMR by an activity multiplier that accurately reflects your lifestyle, from sedentary to extra active.
Be Honest About Your Activity Level: Overestimating your physical activity can lead to inaccurate calorie goals, so choose the most realistic factor for your daily routine.
Refine Your Goal with Caloric Adjustments: To lose weight, create a moderate deficit; to gain weight, aim for a controlled surplus, and monitor your body's response.
Consider Other Factors and Professional Advice: Predictive equations are estimates. Your hydration, individual metabolism, and overall health all matter, so consult a professional for personalized plans.

Understanding the Components of Daily Energy Expenditure

To correctly understand how to calculate your daily energy requirement, you must first break down its components. The total daily energy expenditure (TDEE) is comprised of several factors, with the largest portion coming from your Basal Metabolic Rate (BMR).

Basal Metabolic Rate (BMR)

Your BMR represents the number of calories your body burns at complete rest, maintaining essential functions such as breathing, blood circulation, and organ function. It is the single largest component of your daily energy needs, typically accounting for 60-75% of your TDEE. Factors influencing BMR include Age (decreases with age), Sex (males generally have a higher BMR), Weight and Height (heavier/taller need more energy), and Lean Body Mass (more muscle burns more calories at rest).

The Thermic Effect of Food (TEF)

The thermic effect of food is the energy your body uses to digest, absorb, and metabolize the food you eat. This process accounts for about 10% of your total daily energy expenditure and varies based on the macronutrient composition of your diet.

Physical Activity

This includes all energy expended during voluntary movement and exercise, as well as non-exercise activity thermogenesis (NEAT). This is the most variable component of TDEE and is adjusted using an activity multiplier.

Using Predictive Equations to Calculate Your Energy Needs

The most reliable way to calculate your estimated daily energy requirement (EER) is by using a predictive equation based on your age, sex, weight, height, and physical activity level (PAL). The Mifflin-St Jeor equation is considered one of the most accurate for healthy adults.

The Mifflin-St Jeor Equation

This formula calculates your Basal Metabolic Rate (BMR), which is then multiplied by an activity factor to determine your TDEE.

For Men: $BMR = (10 \times weight\ in\ kg) + (6.25 \times height\ in\ cm) - (5 \times age) + 5$

For Women: $BMR = (10 \times weight\ in\ kg) + (6.25 \times height\ in\ cm) - (5 \times age) - 161$

Applying the Activity Factor

Once you have your BMR, multiply it by the appropriate activity multiplier to find your total daily energy expenditure.

Sedentary: BMR × 1.2 (little or no exercise)
Lightly Active: BMR × 1.375 (light exercise 1–3 days/week)
Moderately Active: BMR × 1.55 (moderate exercise 3–5 days/week)
Very Active: BMR × 1.725 (hard exercise 6–7 days/week)
Extra Active: BMR × 1.9 (very hard daily exercise or physical job)

A Step-by-Step Guide to Calculating Your TDEE

Gather Your Data: Obtain your weight in kilograms, height in centimeters, and age in years. Use conversion tools if needed.
Calculate Your BMR: Use the Mifflin-St Jeor equation based on your sex.
Choose Your Activity Level: Select the activity factor that best matches your lifestyle.
Calculate Your TDEE: Multiply your BMR by your chosen activity factor.
Adjust for Weight Goals: For weight loss, reduce TDEE by 10–25%; for weight gain, add 10–20%.

Comparison of Predictive Equations

Here's a comparison of common equations to estimate BMR and total energy needs:


Feature	Mifflin-St Jeor (1990)	Revised Harris-Benedict (1984)	Katch-McArdle (LBM-based)
Equation (Men)	$10w + 6.25h - 5a + 5$	$13.397w + 4.799h - 5.677a + 88.362$	$500 + 22 \times LBM$
Equation (Women)	$10w + 6.25h - 5a - 161$	$9.247w + 3.098h - 4.330a + 447.593$	$500 + 22 \times LBM$
Accuracy	Most accurate for modern lifestyles in healthy adults.	Can overestimate BMR, especially in obese individuals.	Very accurate but requires Lean Body Mass (LBM).
Key Inputs	Weight (kg), Height (cm), Age (y), Sex	Weight (kg), Height (cm), Age (y), Sex	Lean Body Mass (kg).
Best For	General adult population.	Less accurate than Mifflin-St Jeor.	Athletes and those with measured body composition.

Conclusion: Finding the Right Caloric Target

Calculating your daily energy requirement provides a crucial baseline. While predictive equations offer excellent starting points, they are estimates. The Mifflin-St Jeor formula is recommended for healthy adults due to its improved accuracy. Monitor your progress and make incremental adjustments. Factors like hydration, individual metabolism, and overall health also play a role. Consulting a healthcare professional can provide personalized guidance. Review resources from reputable organizations like the National Institutes of Health (NIH) for more information.

Frequently Asked Questions

BMR (Basal Metabolic Rate) is the energy your body burns at complete rest to maintain vital functions. TDEE (Total Daily Energy Expenditure) is your BMR plus all the calories burned from physical activity and the digestion of food.

The Mifflin-St Jeor equation is generally considered more accurate for estimating calorie needs in today's population and is the preferred method for most health professionals.

After calculating your BMR, you multiply it by a number based on your physical activity level: Sedentary (1.2), Lightly Active (1.375), Moderately Active (1.55), Very Active (1.725), or Extra Active (1.9).

Caloric needs increase during pregnancy, particularly in the second and third trimesters. The increase can range from 200 to 450 extra calories per day, depending on the trimester and pre-pregnancy weight, but it is important to consult a healthcare provider for a specific plan.

Yes, once you have your TDEE, you can create a caloric deficit for weight loss. A common approach is to reduce your intake by 250-330 calories per day to lose about one pound per week, but a healthcare professional can offer tailored advice.

Yes, they do. BMR is higher in individuals with greater lean body mass (muscle) and typically declines as lean body mass decreases with age.

General guidelines are broad averages. Your calculated needs are personalized based on your specific weight, height, age, and activity level, providing a more precise target than a one-size-fits-all figure.