BMI, BMR & TDEE Calculator

About BMI, BMR & TDEE Calculator

This BMI calculator also works as a BMR and TDEE calculator. Enter gender, age, height, weight, and activity level in metric (cm, kg) or imperial (ft/in, lbs) units to get your body mass index with a color-coded category gauge, your basal metabolic rate from the Mifflin-St Jeor equation, and your total daily energy expenditure. It also shows a healthy weight range for your height, calorie targets for cutting (TDEE minus 500) and bulking (TDEE plus 300), daily protein, carb, and fat macros for each goal, and an estimated daily water intake.

How to use

1. Choose Metric or Imperial, then select Male or Female.
2. Enter your Age, Height, and Weight using the sliders or the number boxes; typed values apply when you press Enter or leave the box.
3. Pick your Activity Level from the dropdown, from Sedentary to Extra Active.
4. Read your Body Mass Index on the colored gauge along with its category, BMR, TDEE, and Ideal Weight.
5. Use the Cut, Maintain, and Bulk calorie targets, Daily Macros, and Daily Water as daily guides.

Limitations & notes

• BMI is a screening measure only: it uses fixed adult cutoffs for everyone and cannot tell muscle from fat, so it is not a diagnosis.
• Metric inputs are whole numbers limited to ages 10-100, heights 100-230 cm, and weights 30-200 kg; imperial weight is limited to 1-440 lbs.
• Switching between Metric and Imperial converts the values you entered, rounded to whole cm, kg, inches, and pounds.
• Calorie, macro, and water targets are rough estimates from the Mifflin-St Jeor formula and fixed rules, not personal medical or nutrition advice.

FAQ

How is BMI calculated?

BMI is your weight in kilograms divided by your height in meters squared (kg/m²). For example, 70 kg at 1.75 m gives 70 / 3.0625 = 22.9.

What is a healthy BMI range?

For adults, below 18.5 is underweight, 18.5 to 24.9 is normal weight, 25 to 29.9 is overweight, and 30 or above is obese. BMI is a screening measure, not a diagnosis: it does not tell muscle from fat, so athletes, older adults, and some ethnic groups can be misclassified. Talk to a healthcare professional for a proper assessment.

What is the difference between BMR and TDEE?

BMR is the calories your body burns at complete rest, estimated here with the Mifflin-St Jeor equation. TDEE multiplies BMR by an activity factor from 1.2 (sedentary) to 1.9 (extra active) to estimate what you burn on a typical day, which is your maintenance intake.

How many calories should I eat to lose weight?

The Cut target is your TDEE minus 500 calories a day, roughly 0.5 kg (about 1 lb) of loss per week, and it is never shown below 1,200 kcal. The Bulk target adds 300 calories a day for slow weight gain.

How are the daily macros calculated?

Protein is set at 2.0 g per kg of body weight for cutting, 1.6 g/kg for maintenance, and 1.8 g/kg for bulking. The remaining calories are split 25% to fat and 75% to carbohydrates.