Metabolism Calculator

These calculators help you understand how your body uses energy. The BMR Calculator and Katch-McArdle BMR Calculator estimate the calories your body burns at rest, while the TDEE Calculator layers in your activity level to give a total daily energy figure. From there, the Calorie Deficit Calculator maps out the intake gap you need to hit your goal, and the Keto Macros Calculator breaks down targets for a low-carb approach.

Browse the most-popular list to see which tools visitors rely on most, or open the Trending tab to spot what's rising right now. All calculators are free, require no account, and work on any device.

  • TDEE Calculator
    Calculate your Total Daily Energy Expenditure (TDEE) with this TDEE Calculator. Input gender, age, height, weight, and activity level for accurate results. Supports Harris-Benedict and Mifflin-St Jeor formulas.
  • Fat Grams Per Pound Lost Calculator
    Find out how many calories you must burn to lose a pound of fat. Enter your goal weight loss and timeframe to get the total and daily calorie deficit.
  • Calories to Kilojoules Converter
    Convert calories (kcal) to kilojoules (kJ) and back instantly. Uses the exact factor 1 kcal = 4.184 kJ for accurate energy conversions.
  • BMR Calculator
    Calculate your BMR from sex, birth year, height (cm), and weight (kg) using Harris–Benedict or Mifflin–St Jeor. Get calories/day at rest.
  • Calories Burned Weight Lifting Calculator
    Estimate calories burned weight lifting using the MET formula. Enter your body weight, workout duration, and intensity to get instant kcal results.
  • Blood Sugar Conversion Calculator
    Convert blood sugar (glucose) between mg/dL and mmol/L instantly. Free two-way blood glucose unit converter using the 18.0182 factor.
  • Macros to Calories Calculator
    Convert grams of protein, carbs, fat and alcohol into calories (kcal) instantly. Uses 4/4/9/7 kcal per gram with a full macro breakdown.
  • Maintenance Calories Calculator
    Calculate your maintenance calories (TDEE) from BMR and activity level using the Mifflin-St Jeor equation. See loss and gain targets too.
  • Weight Change Predictor Calculator
    Predict your weekly weight change from daily calorie intake vs TDEE. Estimate gain or loss in pounds and kg using the 3,500 kcal-per-pound rule.
  • Bulking & Cutting Calorie Calculator
    Calculate your daily calorie target for bulking, cutting, or maintaining based on your TDEE. Bulk at 110-120% and cut at 75-85% of maintenance.
  • Goal Weight Date Calculator
    Estimate how many weeks and the target date to reach your goal weight from a daily calorie deficit, using the 7,700 kcal-per-kg rule.
  • Calorie Surplus Calculator
    Calculate your daily calorie target for muscle gain. Add your surplus to TDEE and estimate weekly weight gain in kg and lb.
  • Calories Burned Cycling Calculator
    Estimate calories burned cycling from your weight, ride duration and speed using MET values. Free, instant, science-based cycling calorie calculator.
  • Calories Burned Running Calculator
    Estimate the calories you burn running based on your body weight and distance covered. Free, instant running calorie calculator using kg and km.
  • Weight Loss Timeline Calculator
    Estimate how many days, weeks and months it takes to reach your goal weight from your current weight and daily calorie deficit using the 7700 kcal/kg rule.
  • Weight Loss Timeline Calculator
    Estimate how long it takes to reach your goal weight from a daily calorie deficit. Get weeks, days, and months to hit your target.
  • BMR Calculator (Mifflin-St Jeor)
    Calculate your Basal/Resting Metabolic Rate with the Mifflin-St Jeor equation. Enter weight, height, age and gender to get daily resting calories.
  • Calories Burned Walking Calculator
    Estimate calories burned walking from your weight, walking speed and duration. Get kcal, distance and approximate step count using MET values.
  • Macronutrient Calculator
    Convert your daily calorie target and macro percentage split into grams of protein, carbohydrates, and fat per day. Free macro calculator.
  • Weekly Weight Loss Calculator
    Find the daily calorie deficit needed to lose a set number of pounds per week. Uses the 3,500 calories per pound rule for fast, simple planning.
  • Time to Reach Goal Weight Calculator
    Estimate how many weeks it will take to reach your goal weight based on your daily calorie deficit. Uses the 3,500 calories per pound rule.
  • Calories Burned Swimming Calculator
    Estimate calories burned swimming by stroke, body weight and duration using the standard MET formula. Free, instant, and works for any swimmer.
  • Calories per Pound of Bodyweight Calculator
    Estimate daily maintenance calories using the calories-per-pound rule. Pick cut (×12), maintain (×15), or bulk (×18) to find your target intake fast.
  • HbA1c to Average Glucose Calculator
    Convert HbA1c (%) to estimated average glucose (eAG) in mg/dL and mmol/L using the ADAG formula. Fast, free diabetes conversion tool.

Frequently asked questions

What is the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is the number of calories your body needs at complete rest just to sustain basic functions like breathing and circulation. TDEE (Total Daily Energy Expenditure) multiplies your BMR by an activity factor, giving a realistic estimate of how many calories you actually burn each day.

How accurate are the metabolism estimates?

The calculators use widely cited formulas such as Mifflin-St Jeor, Harris-Benedict, and the Katch-McArdle lean-mass method. All results are statistical estimates based on average population data, not individual metabolic testing. These tools are NOT a substitute for medical or dietitian advice — consult a qualified healthcare professional before making significant dietary changes.

Do you store the information I enter?

No. All calculations run locally in your browser. Your weight, height, age, and activity level are never sent to our servers or saved anywhere between sessions. Refreshing the page resets everything.

Which metabolism calculators do people use most?

The page is ordered by real visitor usage — the top entries are the ones people find most useful. Switch to the Trending tab to see which tools are climbing fastest right now, or check Recently Added for new arrivals.

Is it free to use?

Yes, every tool in this collection is completely free with no sign-up, subscription, or limits on how many times you run a calculation. They work on any modern phone, tablet, or desktop browser.

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