Energy Converter
Convert energy units: joules, calories, kilocalories and kilowatt-hours.
Energy conversions are needed in physics, engineering, nutrition, and utility billing. Joules, calories, kilowatt-hours, BTU, and electronvolts all measure the same physical quantity but in very different contexts. Food energy is measured in kilocalories (kcal, often called "Calories" with capital C). Electricity bills use kilowatt-hours (kWh). Industrial heat processes use BTU. This converter handles all common energy units with context for each.
📋 How to Use This Calculator
Enter an energy value and select the source unit. All equivalents are displayed. The nutrition tab specifically handles food energy — converting between kcal, kJ, and the energy in grams of each macronutrient (protein and carbs: 4 kcal/g; fat: 9 kcal/g; alcohol: 7 kcal/g). The electricity tab calculates the cost of energy at your electricity tariff rate.
💡 Key Facts & Information
Key conversions: 1 kcal = 4,184 J = 4.184 kJ = 3.968 BTU. 1 kWh = 3,600,000 J = 3,600 kJ = 860 kcal = 3,412 BTU. 1 BTU = 1,055 J = 0.252 kcal. Calorie confusion: 1 food Calorie (capital C) = 1 kilocalorie (kcal) = 1,000 small calories. Always check whether a nutrition label uses kcal or kJ. Indian electricity tariff: residential rates ₹3–8 per kWh (unit) depending on state and consumption slab. A 1,500W air conditioner running 8 hours uses 12 kWh — approximately ₹60–96 per day at ₹5–8/unit. A 100W bulb running 10 hours uses 1 kWh (1 unit).