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.
- Body Composition Calculator
- Metabolism Calculator
- Nutrition Calculator
- Heart Health Calculator
- Pregnancy Calculator
- Fitness Calculator
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Fat Grams Per Pound Lost CalculatorFind 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.
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Maintenance Calories CalculatorCalculate your maintenance calories (TDEE) from BMR and activity level using the Mifflin-St Jeor equation. See loss and gain targets too.
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Bulking & Cutting Calorie CalculatorCalculate your daily calorie target for bulking, cutting, or maintaining based on your TDEE. Bulk at 110-120% and cut at 75-85% of maintenance.
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Goal Weight Date CalculatorEstimate 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.
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Calorie Surplus CalculatorCalculate your daily calorie target for muscle gain. Add your surplus to TDEE and estimate weekly weight gain in kg and lb.
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Calories Burned Cycling CalculatorEstimate calories burned cycling from your weight, ride duration and speed using MET values. Free, instant, science-based cycling calorie calculator.
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Calories Burned Running CalculatorEstimate the calories you burn running based on your body weight and distance covered. Free, instant running calorie calculator using kg and km.
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Weight Loss Timeline CalculatorEstimate 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.
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Weight Loss Timeline CalculatorEstimate how long it takes to reach your goal weight from a daily calorie deficit. Get weeks, days, and months to hit your target.
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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.
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Calories Burned Walking CalculatorEstimate calories burned walking from your weight, walking speed and duration. Get kcal, distance and approximate step count using MET values.
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Macronutrient CalculatorConvert your daily calorie target and macro percentage split into grams of protein, carbohydrates, and fat per day. Free macro calculator.
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Weekly Weight Loss CalculatorFind 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.
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Time to Reach Goal Weight CalculatorEstimate 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.
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Calories Burned Swimming CalculatorEstimate calories burned swimming by stroke, body weight and duration using the standard MET formula. Free, instant, and works for any swimmer.
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Macros to Calories CalculatorConvert grams of protein, carbs, fat and alcohol into calories (kcal) instantly. Uses 4/4/9/7 kcal per gram with a full macro breakdown.
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Calories per Pound of Bodyweight CalculatorEstimate daily maintenance calories using the calories-per-pound rule. Pick cut (×12), maintain (×15), or bulk (×18) to find your target intake fast.
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HbA1c to Average Glucose CalculatorConvert HbA1c (%) to estimated average glucose (eAG) in mg/dL and mmol/L using the ADAG formula. Fast, free diabetes conversion tool.
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Blood Sugar Conversion CalculatorConvert blood sugar (glucose) between mg/dL and mmol/L instantly. Free two-way blood glucose unit converter using the 18.0182 factor.
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Weight Gain Calorie CalculatorCalculate daily calories needed to gain weight at your target rate using TDEE plus a calorie surplus (Mifflin-St Jeor BMR). Free and easy to use.
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Daily Calorie Deficit Weight Loss CalculatorEstimate how long it takes to lose weight from a daily calorie deficit. Enter kg to lose and your daily kcal deficit to see days, weeks and weekly loss.
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Katch-McArdle BMR CalculatorCalculate your Basal Metabolic Rate with the Katch-McArdle formula using body weight and body fat percentage for a lean-mass based estimate.
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BMR Calculator (Mifflin-St Jeor)Calculate your Basal Metabolic Rate with the Mifflin-St Jeor equation. Enter weight, height, age and gender to find daily resting calories and TDEE.
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Katch-McArdle BMR CalculatorEstimate your basal metabolic rate with the Katch-McArdle formula based on lean body mass. Enter weight and body fat % to get daily resting calories.
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.
