Kilowatt-hours to British thermal units (IT) (kWh to BTU)

The formula

BTU = kWh × 3,412.141633

Where the factor comes from — each unit by its definition, then its size in SI:

• 1 kWh = 1000 × Wh = 3,600,000 J
• 1 BTU = 1055.05585262 × J = 1,055.05585262 J

Dividing the two SI sizes gives the factor: 3,412.14163313 (rounded for display; the underlying ratio is fixed by the definitions). The reverse factor is 0.000293071070172.

The SI unit of energy is the joule. Food labels use kilocalories, electricity bills kilowatt-hours, heating specs BTU and particle physics electronvolts — the same quantity in five costumes.

Worked examples

• A day's food (2000 kcal): 2.32444 kWh = 7,931.33 BTU — 2.32444 × 3,412.141633 = 7,931.33
• A 1 kW heater run for one hour: 1 kWh = 3,412.14 BTU — 1 × 3,412.141633 = 3,412.14
• Lifting 1 kg through 1 m at standard gravity (9.80665 J): 2.72407 × 10⁻⁶ kWh = 0.00929491 BTU — 2.72407 × 10⁻⁶ × 3,412.141633 = 0.00929491
• A visible-light photon (2 eV): 8.90098 × 10⁻²⁶ kWh = 3.03714 × 10⁻²² BTU — 8.90098 × 10⁻²⁶ × 3,412.141633 = 3.03714 × 10⁻²²

Frequently asked questions