What Is a Calorie?
A calorie is a unit of energy. On food labels, “Calories” actually means kilocalories (kcal): the energy needed to raise the temperature of one kilogram of water by one degree Celsius. Protein and carbohydrates provide about 4 kcal per gram, fat about 9, and alcohol about 7.
kcal and kJ
Some countries label food energy in kilojoules; 1 kcal ≈ 4.184 kJ.
Energy Balance
Daily energy needs depend on basal metabolic rate and activity, often summarized as total daily energy expenditure.
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Calorie Calculator (TDEE)
Find your daily calorie needs using the Mifflin-St Jeor formula.
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Macro Calculator
Daily calories and protein, carb, and fat targets from your TDEE and goal.
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Calories Burned Calculator
Estimate calories burned by activity, body weight, and duration using MET values.
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🔗 Related Terms
More Health & Fitness Terms
- Body Composition
- Body Fat Percentage
- Body Mass Index (BMI)
- Calorie Deficit
- Circadian Rhythm
- Estimated Due Date (EDD)
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Last updated: September 29, 2026. This definition is for general educational purposes only. It is not financial, investment, tax, legal, or medical advice, and it does not recommend any product or course of action. For decisions about your own situation, consult a qualified professional.