BMR & TDEE Calculator

📖 Overview

Cutting or bulking starts with knowing what you actually burn in a day. Basal metabolic rate is the minimum energy your body needs at rest and accounts for roughly sixty to seventy percent of total expenditure; multiply it by an activity factor and you get total daily energy expenditure, which is the number worth planning meals around. This tool computes basal metabolic rate with Mifflin-St Jeor and can switch to Katch-McArdle, which needs a body fat reading but is more accurate for muscular people. Pick a cut, maintain or bulk goal and a rate of adjustment and it returns your daily calorie target, the expected weekly change in body weight, and the gram split across protein, fat and carbohydrate. It also back-solves a healthy weight range from a BMI of 18.5 to 23.9 so you can judge whether your goal is sensible. The activity factor is where most people go wrong. Selecting moderately active when you sit at a desk and train three times a week will overshoot by several hundred calories, which is enough to turn a planned cut into maintenance. When in doubt, pick the lower band and adjust after two weeks of tracking your actual weight trend.

✨ Features

• Computes basal metabolic rate with Mifflin-St Jeor and can switch to Katch-McArdle when you have a body fat figure A comparison between the two formulas is shown when you have a body fat figure, so the spread is visible.
• Six activity factors from sedentary to heavy physical work, so the total daily figure matches how you actually live The activity levels are described with concrete examples rather than abstract labels.
• Several adjustment rates for cutting and bulking, each returning a daily calorie target and expected weekly weight change The pace options translate into an explicit daily deficit or surplus in calories.
• Converts the three macronutrients into grams, with protein settable per kilogram of body weight Carbohydrate takes the remainder, so the three figures always sum to your target.
• Back-solves a healthy weight range from BMI 18.5 to 23.9 to judge whether your target is reasonable Ranges are given for both sexes using the same BMI band.
• Recalculates live as you change target weight or body fat, so you need not press the button repeatedly Switching units between metric and imperial recalculates without clearing your entries.

🚀 How to use

1. Select sex and enter your age, height and weight
2. Choose your activity level, six options from sedentary to high intensity
3. Pick cut, maintain or bulk and set how aggressive the adjustment should be
4. If you know your body fat percentage, enter it to switch to the more accurate formula
5. Read your calorie target, weekly weight change and macronutrient grams

⚠️ Notes

• Equations estimate: both formulas are population averages, and individual variation can reach plus or minus ten percent, so use the output as a starting point and refine it against measured results
• Not medical advice: if you are pregnant, breastfeeding, have a metabolic condition or an eating disorder, follow clinical guidance rather than self-restricting, and children and adolescents need different equations entirely
• Very low targets carry risk: the tool warns when your target falls too far below basal needs, since prolonged under-eating costs muscle and depresses metabolism, and the tool marks when a target falls below a prudent floor
• Weight change is modelled: the weekly figure uses roughly 7700 calories per kilogram of fat, and early water swings will move the real number, so weigh yourself under the same conditions and read a two-week trend
• Numbers only: a zero or out-of-range age, height or weight produces a message instead of a result, and out-of-range values are rejected rather than silently accepted