Energy Converter

Energy Conversion Table

Unit Joule (J) Calorie (cal) Btu (IT) kWh eV
1 Joule10.2390.0009482.78e-76.24e+18
1 Calorie4.18410.003971.16e-62.61e+19
1 Btu (IT)1055.06252.1610.0002936.59e+21
1 kWh3.6e+6860.423412.1412.25e+25
1 eV1.602e-193.83e-201.52e-224.45e-261

Energy Converter Overview

1. Core Idea

Convert any energy unit by routing through joules (the base SI unit). Then scale to the target using exact factors.

2. Key Factors

  • 1 kJ = 1000 J
  • 1 cal = 4.184 J
  • 1 kcal = 4184 J
  • 1 Wh = 3600 J
  • 1 kWh = 3.6×10⁶ J
  • 1 BTU = 1055.06 J
  • 1 ft·lb = 1.35582 J
  • 1 N·m = 1 J

3. Quick Examples

  • 1 kWh = 3.6 MJ = 860.42 kcal
  • 250 cal = 1046 J ≈ 1.046 kJ
  • 5000 J = 5 kJ = 1.195 kcal
  • 1500 ft·lb ≈ 2033.7 J

4. 3-Step Example

Convert 2.2 kWh to kJ

  1. kWh → J: 2.2 × 3.6×10⁶ = 7.92×10⁶ J
  2. Divide by 1000 for kJ
  3. = 7920 kJ

5. Uses

Appliances (kWh), nutrition (kJ/kcal), heating & cooling (BTU), mechanical work (ft·lb / N·m), batteries (Wh), physics problems (J).

6. Accuracy & Tips

  • Always convert via joules for chain conversions.
  • Mental: kcal ×4 ≈ kJ; kWh ×3600 = kJ; BTU ×1.055 ≈ kJ.
  • Round: whole kcal / nearest 5 kJ for labeling.

7. More Examples

SourceTargetResult
1.5 kWhkcal1.5×3.6×10⁶ ÷ 4184 = 1291.6
4200 Jkcal≈1.00
860 kcalkWh860×4184 ÷ 3.6×10⁶ = 1.00
12 BTUkJ12×1055.06 ÷ 1000 = 12.66

8. FAQ

Why convert through joules?

It standardizes operations and prevents cumulative rounding across multiple direct factors.

kcal vs Cal?

Food Calorie (capital C) = kilocalorie = 4184 J.