Harris-Benedict Calculator
HealthCalculate your BMR and total daily energy expenditure using the revised 1984 Harris-Benedict equation, adjusted for your activity level in seconds.
Gender
Age
yrs
1580
Weight
kg
30200
Height
cm
100250
Activity Level
Total Daily Energy Expenditure
0
BMR (Revised Harris-Benedict)
0
Weight Loss Calories (−500)
0
Weight Gain Calories (+500)
0
What is a Harris-Benedict?
The Harris-Benedict Calculator estimates your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the revised 1984 Harris-Benedict equation (Roza & Shizgal), the version most commonly cited in modern nutrition guidance and fitness apps. Unlike the original 1919 formula, the 1984 revision was recalculated using updated body composition data, producing estimates that better reflect typical adult metabolism.
This calculator takes your sex, age, weight, height, and activity level, then applies an activity multiplier to your BMR to estimate how many calories you burn in a typical day. This is distinct from the BEE Calculator on this site, which uses the original 1919 equation and reports a resting-only figure with no activity adjustment — this tool is the one to use for everyday calorie planning.
How to use this Harris-Benedict calculator
- Select your Gender — Male or Female — since the equation applies different coefficients for each.
- Enter your Age in years using the slider.
- Enter your Weight in kilograms.
- Enter your Height in centimeters.
- Choose your Activity Level from the five options shown, each with a description and multiplier to help you pick accurately.
- Review your Total Daily Energy Expenditure result, along with your BMR and the weight loss/gain calorie targets shown alongside it.
- Recalculate periodically as your weight or activity level changes to keep your calorie targets accurate.
Formula & Methodology
The revised 1984 Harris-Benedict equation calculates BMR separately for men and women:Men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) − (5.677 × age in years) Women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) − (4.330 × age in years)TDEE is then calculated by multiplying BMR by an activity factor:TDEE = BMR × Activity Multiplier| Activity Level | Multiplier | |---|---| | Sedentary | ×1.2 | | Lightly Active | ×1.375 | | Moderately Active | ×1.55 | | Very Active | ×1.725 | | Extra Active | ×1.9 | Worked example: A 30-year-old man weighing 70 kg, 170 cm tall, who is moderately active, has a BMR of 88.362 + (13.397 × 70) + (4.799 × 170) − (5.677 × 30) = 88.362 + 937.79 + 815.83 − 170.31 ≈ 1,672 kcal/day. Multiplying by the moderate activity factor of 1.55 gives a TDEE of approximately 2,591 kcal/day — with a weight loss target near 2,091 kcal/day and a weight gain target near 3,091 kcal/day.
Frequently Asked Questions
The Harris-Benedict equation is a predictive formula that estimates your Basal Metabolic Rate (BMR) from weight, height, age, and sex, then multiplies it by an activity factor to estimate Total Daily Energy Expenditure (TDEE). This calculator uses the commonly cited revised 1984 version (Roza & Shizgal), which updated the original 1919 coefficients using a larger, more representative dataset.
The [BEE Calculator](/bee-calculator/) uses the original 1919 Harris-Benedict equation and reports a resting-only figure with no activity adjustment. This Harris-Benedict Calculator uses the revised 1984 equation and applies an activity multiplier to estimate your full Total Daily Energy Expenditure, making it more directly useful for everyday calorie planning.
Choose Sedentary if you have a desk job with little or no exercise, Lightly Active for 1-3 days per week of exercise, Moderately Active for 3-5 days per week, Very Active for 6-7 days per week of hard exercise, and Extra Active if you combine intense training with a physically demanding job. Selecting a level closer to your true weekly activity avoids overestimating your calorie needs.
The revised 1984 Harris-Benedict equation remains widely used and reasonably accurate for most adults, though research generally shows the Mifflin-St Jeor equation — used in the [BMR Calculator](/bmr-calculator/) — is slightly more accurate on average for contemporary populations. Both are useful estimates; individual metabolic rate can vary from any predictive formula by 10% or more.
Subtracting roughly 500 calories per day from your TDEE typically produces about 0.5 kg (1 lb) of weight loss per week, while adding 500 calories supports a similar rate of weight gain. This calculator shows both adjusted figures automatically alongside your baseline TDEE.
BMR is your resting energy need with no activity included, while TDEE multiplies BMR by an activity factor to estimate your true total daily calorie burn including exercise and daily movement. TDEE is the more useful number for setting an actual daily calorie target.
Yes — both BMR and TDEE change as your weight changes, so recalculating every few weeks during an active weight loss or gain phase keeps your calorie targets accurate. A rapid initial weight change (especially water weight) can otherwise throw off your calorie planning if you don't adjust.
Yes — use the Weight Gain Calories (+500) figure as a starting point for a lean bulk, then adjust based on your actual rate of weight gain over 2-3 weeks. Pairing this with the [Macro Calculator](/macro-calculator/) helps ensure the extra calories go toward the right protein, carb, and fat split for muscle growth.
No — the Harris-Benedict equation only uses total weight, not lean body mass, so it doesn't distinguish between fat and muscle. If you know your body fat percentage, the [Katch-McArdle Calculator](/katch-mccardle-calculator/) uses lean body mass instead and can be more accurate for very lean or very muscular individuals.
This calculator uses metric units — weight in kilograms and height in centimeters — consistent with the original Harris-Benedict research and most international nutrition tools. Convert pounds to kilograms by dividing by 2.205, and inches to centimeters by multiplying by 2.54, if needed.
Predictive equations like Harris-Benedict are estimates based on population averages and can be off by several hundred calories for any given individual due to genetics, muscle mass, and metabolic differences. Treat your result as a starting point, then adjust up or down based on your actual weight trend over 2-3 weeks of consistent tracking.
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