How many kcal is 100 BTU?

100 × 0.251996 = 25.2 kcal. A small snack might be 200-400 kcal.

A water heater is 40,000 BTU — how many kcal/h?

40,000 × 0.251996 = 10,080 kcal/h. Typical residential water heater.

Is 1 BTU exactly 0.252 kcal?

1 BTU (IT) = 1055.056 J ÷ 4.184 J/kcal = 0.251996 kcal. We typically use 0.252. See [BTU to Joules](/energy/btu-to-joules/) for the SI path.

Why multiply by 0.252?

BTU is larger than kcal. 1 BTU = 252 cal = 0.252 kcal.

BTU (IT) to Kilocalories (kcal) Converter

Enter a value to instantly convert between energy units.

From

Precision4 dp

1 BTU (IT) = 0.2522 Kilocalorie

Key Formulas

Kilocalorie → Kilojoule

kJ = kcal × 4.184

Kilojoule → Kilocalorie

kcal = kJ × 0.239006

Kilowatt-Hour → Joule

J = kWh × 3600000

Joule → Kilowatt-Hour

kWh = J × 2.77778e-7

Formula

kcal = BTU × 0.251996

One BTU (IT) equals 0.252 kilocalories. BTU is the standard unit for US heating and cooling equipment, while kcal is used in nutrition. Converting between them helps compare food energy to heating equipment output.

Source: NIST SP 811, Table B.8

Frequently Asked Questions

Real-World Examples

An energy auditor comparing 1 BTU of furnace output to food energy — 0.252 kcal.

1 BTU = 0.252 kcal

A boiler rated at 10,000 BTU/h produces 2520 kcal/h — useful for comparison.

10000 BTU = 2520 kcal

A heating engineer calculating 1000 BTU from a space heater reports 252 kcal for the comparison.

1000 BTU = 252 kcal

A residential furnace rated at 50,000 BTU/h produces 12,600 kcal/h for the efficiency rating.

50000 BTU = 12600 kcal

kcal to kj kj to kcal kwh to joules joules to kwh btu to joules calories to joules

BTU (IT) to Kilocalories (kcal) Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

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