How many kcal should I eat per day?

Average is 2,000 kcal for women, 2,500 kcal for men. These are food Calories (kilocalories), not the small gram-calories used in chemistry. 1 food Cal = 1 kcal = 4.184 kJ.

Kilowatt-hour is energy, not power. 1 kWh = 3.6 million joules. A 100 W bulb left on for 10 hours uses 1 kWh. Your electricity bill charges per kWh.

BTU vs calorie - which is bigger?

1 BTU is about 252 cal or 0.252 kcal or 1,055 J. BTU is the amount of heat to warm 1 lb water by 1 degree F. It is still used for gas and furnaces in the US.

🔋 Energy Converter

Food labels show Calories (kilocalories), physics textbooks use joules, electric bills use kilowatt-hours, furnaces use BTU. And a food Calorie is 1,000 physics calories.

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Last updated September 10, 2026 — conversions use exact ISO unit definitions.