Calculator
Formula Used
BMI Formula: BMI = weight in kilograms ÷ height in meters squared.
Original Harris Benedict for men: BMR = 66.473 + 13.7516W + 5.0033H - 6.755A.
Original Harris Benedict for women: BMR = 655.0955 + 9.5634W + 1.8496H - 4.6756A.
Revised Harris Benedict for men: BMR = 88.362 + 13.397W + 4.799H - 5.677A.
Revised Harris Benedict for women: BMR = 447.593 + 9.247W + 3.098H - 4.330A.
TDEE Formula: TDEE = BMR × activity factor. W means weight in kilograms. H means height in centimeters. A means age in years.
How To Use This Calculator
Select your unit system first. Enter your sex, age, height, and weight. Pick the activity level that best describes your normal week. Choose the original or revised Harris Benedict equation. Select a goal and calorie adjustment if needed. Press calculate. Your BMI, BMR, TDEE, calorie target, healthy weight range, and macro estimate will appear above the form.
Example Data Table
| Sex | Age | Height | Weight | Activity | BMI | BMR | TDEE |
|---|---|---|---|---|---|---|---|
| Male | 30 | 175 cm | 75 kg | Light | 24.49 | 1702 kcal | 2340 kcal |
| Female | 28 | 165 cm | 62 kg | Moderate | 22.77 | 1391 kcal | 2156 kcal |
| Male | 45 | 180 cm | 92 kg | Sedentary | 28.40 | 1841 kcal | 2209 kcal |
| Female | 36 | 160 cm | 70 kg | Very active | 27.34 | 1396 kcal | 2408 kcal |
About This BMI And Harris Benedict Calculator
This calculator joins two useful health estimates in one place. BMI describes weight status by comparing body weight with height. Harris Benedict estimates basal metabolic rate, also called BMR. BMR is the energy your body may use at rest. Together, these values support simple planning. They do not replace medical advice. They do give a clear starting point.
Why Both Numbers Matter
BMI alone cannot show muscle mass, body fat pattern, age, or training level. A strong athlete may show a high BMI while staying healthy. A sedentary person may show a normal BMI yet still need better habits. BMR adds another layer. It estimates daily energy needs before activity. When activity is added, the tool gives total daily energy expenditure. This number helps with weight maintenance, loss, or gain planning.
Using Results Safely
Use the output as an estimate. Track real weight change for two to four weeks. Then adjust calories slowly. A small deficit can support fat loss. A small surplus can support gradual gain. Very low calorie targets can be risky. Pregnant people, teens, older adults, and patients with illness should seek professional guidance before changing diet.
Understanding Activity Factors
The activity factor multiplies BMR. Low activity uses a small multiplier. Intense training uses a larger multiplier. Choose the level that matches an average week, not your best day. Office work with short walks is usually sedentary or lightly active. Hard exercise most days may be very active. Manual labor plus training can be extra active.
Better Planning With The Table
The example table shows how inputs change the final estimate. Compare height, weight, age, sex, and activity together. Small changes can shift TDEE. Use the download buttons to save your own report. A saved record makes follow up easier. It also helps compare future measurements.
Final Notes
BMI and BMR are screening tools. They are not final diagnoses. Sleep, food quality, stress, medication, and hormones also matter. Use the formulas as a guide, then combine them with practical habits and qualified support. Review trends, not single days, because hydration and sodium can move scale weight quickly without changing fat.
FAQs
1. What does this calculator measure?
It measures BMI, BMR, TDEE, goal calories, healthy weight range, and basic macro targets. It combines body mass index with the Harris Benedict energy equation.
2. Is BMI always accurate?
BMI is a screening number. It does not measure body fat directly. Muscle mass, bone structure, age, and body composition can affect interpretation.
3. What is BMR?
BMR means basal metabolic rate. It estimates calories your body may burn at rest for breathing, circulation, temperature control, and basic cell activity.
4. What is TDEE?
TDEE means total daily energy expenditure. It multiplies BMR by an activity factor to estimate daily calories used with movement and exercise.
5. Which Harris Benedict version should I use?
The revised version is often preferred for modern estimates. The original version is included for comparison, older references, and educational use.
6. Can I use this for weight loss?
Yes. Choose weight loss and select a moderate calorie reduction. Avoid extreme deficits unless supervised by a qualified health professional.
7. Why are macro estimates included?
Macros give a simple food planning view. Protein, fat, and carbohydrate targets help translate calorie results into daily meal structure.
8. Should medical conditions change my result?
Medical conditions, medications, pregnancy, and eating disorders can change energy needs. Ask a qualified professional before making major diet changes.