Energy Converter
Convert joules, calories, kWh, BTU, and electronvolts for science, cooking, and engineering.
Energy Conversion
Metric (Joules)
Food Energy
💡 Food labels use "Calorie" (capital C) = 1 kcal
Electricity
💡 kWh is the unit on your electricity bill
Other Units
Real-World Energy Examples
⚡ Bonus: Calculate Your Electricity Cost
ZAR per kWh (avg 2024)
Tip: Type in any energy unit and all others update instantly. Use copy buttons (📋) to copy values.
How it works
Base Unit: 1 joule (J) Energy Conversions to Joules: 1 kJ = 1,000 J | 1 MJ = 1,000,000 J 1 cal = 4.184 J | 1 kcal = 4,184 J 1 Wh = 3,600 J | 1 kWh = 3,600,000 J 1 BTU = 1,055 J | 1 eV = 1.602 × 10⁻¹⁹ J KEY CONVERSIONS: 1 kWh = 3,600 kJ = 860 kcal (approximately) Food "Calorie" (capital C) = 1 kcal (kilojoule) kWh is the unit on your electricity bill Real-World Energy: Running 1 km ≈ 60 kcal = 251 kJ Slice of bread ≈ 80 kcal = 335 kJ Boiling 1L water ≈ 100 Wh 1 kWh electricity: SA ~R3.50 | UK ~30p | US ~$0.16
Enter an energy amount in any unit and see the conversion to all others instantly. Supports joules, calories, kilocalories (food energy), watt-hours (electricity), BTU, and electronvolts. Understand the relationship between the energy in food, electricity bills, and scientific measurements. Bonus: Calculate your daily electricity cost based on local rates.
Why this matters
Energy is measured in different ways depending on context. Food uses calories (actually kilocalories); electricity uses watt-hours; science uses joules; heating uses BTU. A food "Calorie" (capital C) is 1 kilocalorie. Your electricity bill shows kWh. Understanding these conversions helps you understand energy consumption, food nutrition, and electricity costs. This calculator makes it clear.
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Formulas, examples, and tips explained in plain English