Calculator Form
This calculator is for educational planning. Medical conditions, pregnancy, recovery, and athletic demands may require professional advice.
Example Data Table
| Profile | Sex | Age | Weight | Height | Activity | Formula | BMR | TDEE |
|---|---|---|---|---|---|---|---|---|
| Sample 1 | Male | 32 | 78 kg | 178 cm | Moderately active | Revised | 1805.89 kcal/day | 2799.12 kcal/day |
| Sample 2 | Female | 29 | 62 kg | 168 cm | Lightly active | Original | 1441.68 kcal/day | 1982.31 kcal/day |
Formula Used
Original Harris-Benedict Formula
Men: BMR = 66.473 + 13.7516 × weight(kg) + 5.0033 × height(cm) − 6.755 × age(years)
Women: BMR = 655.0955 + 9.5634 × weight(kg) + 1.8496 × height(cm) − 4.6756 × age(years)
Revised Harris-Benedict Formula
Men: BMR = 88.362 + 13.397 × weight(kg) + 4.799 × height(cm) − 5.677 × age(years)
Women: BMR = 447.593 + 9.247 × weight(kg) + 3.098 × height(cm) − 4.330 × age(years)
Daily Energy and Goal Formulas
TDEE: TDEE = BMR × activity factor
Goal calories: Goal calories = TDEE + daily calorie adjustment
Weekly estimate: Weekly change (kg) ≈ (daily calorie adjustment × 7) ÷ 7700
The calculator also converts imperial inputs to metric values before running the equations. BMI and a suggested protein range are added as planning aids.
How to Use This Calculator
- Select metric or imperial units.
- Choose sex and enter age.
- Enter current body weight and height.
- Pick original, revised, or compare mode.
- Choose the activity level that best matches daily movement.
- Select a goal such as maintenance, fat loss, lean gain, or custom adjustment.
- Press Calculate Now to show results above the form.
- Use the export buttons to save the outcome as CSV or PDF.
Frequently Asked Questions
1) What does the Harris-Benedict calculator estimate?
It estimates basal metabolic rate and then multiplies that value by an activity factor to predict total daily energy expenditure.
2) Why are there original and revised formulas?
The original equation is older. The revised version updates the constants and is often preferred for modern planning comparisons.
3) What is BMR?
BMR is the estimated energy your body needs at complete rest for core functions like breathing, circulation, and temperature control.
4) What is TDEE?
TDEE means total daily energy expenditure. It combines resting needs with movement and exercise through an activity multiplier.
5) Can this calculator help with fat loss?
Yes. Choose a calorie deficit goal. The tool estimates a lower daily target and shows an approximate weekly weight-change pace.
6) Is the result exact for everyone?
No. It is a planning estimate. Muscle mass, hormones, health status, medications, and training load can shift real energy needs.
7) Why does the page show protein guidance too?
Protein goals are often useful when planning maintenance, cutting, or gaining phases. The range here is a practical companion estimate.
8) Should I rely on this during pregnancy or illness?
Use caution. Special health conditions can change nutrition needs substantially, so tailored advice from a qualified professional is better.