Advanced Harris-Benedict BMR Calculator

Calculator Inputs

Sex

Age (years)

Unit System

Height (cm)

Weight (kg)

Equation Version

Activity Level

Calorie Goal

Goal Percent

Use a positive percentage. The calculator applies direction automatically for loss or gain.

Protein %

Carbohydrate %

Fat %

Formula Used

Original Equation

Men: BMR = 66.4730 + (13.7516 × weight in kg) + (5.0033 × height in cm) − (6.7550 × age in years)

Women: BMR = 655.0955 + (9.5634 × weight in kg) + (1.8496 × height in cm) − (4.6756 × age in years)

Revised Equation

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)

Energy Planning

Estimated Daily Calories: TDEE = BMR × activity factor

Goal Calories: Goal = TDEE × (1 + adjustment %)

Macro Grams: Protein = calories × protein% ÷ 4, carbs = calories × carb% ÷ 4, fat = calories × fat% ÷ 9

How to Use This Calculator

Select your sex, age, and preferred unit system.
Enter height and weight using metric or imperial values.
Choose the original or revised Harris-Benedict equation.
Pick your activity level or enter a custom multiplier.
Set a calorie goal for maintenance, fat loss, gain, or a custom adjustment.
Choose macro percentages for protein, carbohydrates, and fat.
Press Calculate BMR to show results above the form.
Review the graph, summary table, macro targets, and export buttons.

Example Data Table

Profile	Formula	BMR	Activity	Estimated Daily Calories
Male, 30 years, 178 cm, 78 kg	Revised	1,817.24 kcal	Moderately Active	2,816.72 kcal
Female, 28 years, 165 cm, 60 kg	Revised	1,392.34 kcal	Lightly Active	1,914.47 kcal
Male, 45 years, 172 cm, 92 kg	Revised	1,890.85 kcal	Sedentary	2,269.02 kcal
Female, 52 years, 160 cm, 70 kg	Original	1,377.34 kcal	Very Active	2,376.91 kcal

Frequently Asked Questions

1. What does BMR mean?

BMR means basal metabolic rate. It estimates how many calories your body uses at complete rest for basic functions such as breathing, circulation, and temperature control.

2. What is the difference between BMR and daily calories?

BMR reflects resting energy use only. Daily calories, often called TDEE, add movement and exercise through an activity multiplier, producing a more practical nutrition target.

3. Which Harris-Benedict version should I choose?

Many users prefer the revised equation because it updates the older constants. The original formula is still useful when you want historical comparison or legacy reference values.

4. Is this calculator useful for fat loss planning?

Yes. Choose a fat-loss goal and the calculator applies a calorie deficit to your estimated daily calories. Pair the result with protein planning and consistent progress tracking.

5. Can I use imperial units?

Yes. Switch the unit system to imperial and enter feet, inches, and pounds. The calculator converts those values internally before applying the equations.

6. Why does the activity level matter so much?

The activity factor scales your BMR into estimated daily calories. Small multiplier changes can shift your target noticeably, especially for active training schedules or physically demanding jobs.

7. Are macro targets required for BMR?

No. BMR only needs sex, age, height, and weight. Macro targets are optional planning outputs that convert calorie goals into grams of protein, carbohydrates, and fat.

8. Is this calculator a medical diagnosis tool?

No. It provides educational estimates. Medical nutrition therapy, clinical weight management, and disease-related energy needs should be reviewed with a qualified healthcare professional.