How many BTU is 1 kilocalorie?

1 kilocalorie (kcal) equals approximately 3.96567 BTU. The exact conversion uses 1 kcal = 4,184 J and 1 BTU = 1,055.06 J, giving 4184 / 1055.06 ≈ 3.96567.

How many kcal is 1 BTU?

1 BTU equals approximately 0.25216 kcal. This is the reciprocal of 3.96567.

What is a kilocalorie (kcal)?

A kilocalorie is 1,000 thermochemical calories. It is also the "Calorie" (capital C) used on food nutrition labels. So when a snack says 200 Calories, it means 200 kcal.

Which calorie definition does this converter use?

This tool uses the thermochemical calorie (cal_th), defined as exactly 4.184 joules. Therefore 1 kcal = 4,184 J. The International Table calorie (4.1868 J) differs by less than 0.07% — negligible for practical conversions.

Why would I convert kcal to BTU?

BTU is the standard energy unit in US heating, HVAC, and appliance ratings, while kcal appears in nutrition, chemistry, and European engineering. Converting between them is needed when comparing food energy to fuel energy, sizing heating systems, or working with mixed-unit specifications.

How do I convert a 2,000 kcal diet to BTU?

Multiply by 3.96567: 2,000 × 3.96567 ≈ 7,931 BTU. That is roughly the energy in one-fifth of a cubic foot of natural gas.

Kilocalories to BTU Converter

Name: Kilocalories to BTU Converter
Availability: InStock
Author: Nham Vu

Enter kilocalories (kcal) to get BTU instantly, or enter BTU to reverse-convert — includes a quick-reference table for common values.

Convert

Kilocalories (kcal)

Result

British Thermal Units (BTU)

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Reverse Conversion

British Thermal Units (BTU)

Kilocalories (kcal)

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Formula: BTU = kcal × 3.96567 | kcal = BTU × 0.25216

Reference Table

kcal	BTU

What is a kcal? A kilocalorie (kcal) is 1,000 thermochemical calories — the same unit food labels call a "Calorie" (capital C). 1 kcal = 4,184 joules.

What is a BTU? A British Thermal Unit is the energy needed to raise 1 lb of water by 1 °F. It is the standard unit for US HVAC, heating equipment, and appliance ratings. 1 BTU = 1,055.06 joules.

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Summary

Enter kilocalories (kcal) to get BTU instantly, or enter BTU to reverse-convert — includes a quick-reference table for common values.

How it works

Enter a kilocalorie (kcal) value in the top input field.
The BTU result appears instantly — no button press needed.
Use the reverse field to convert BTU back to kilocalories.
Click "Copy" next to any result to copy it to your clipboard.
Check the reference table for common kcal-to-BTU values at a glance.

Use cases

Compare food energy on nutrition labels (kcal) to BTU-based appliance or fuel ratings.
Size HVAC or heating systems when energy data is given in kilocalories.
Convert chemistry lab heat values from kcal to BTU for US engineering reports.
Translate dietary energy to BTU for building energy modeling or metabolic studies.
Cross-check boiler or water heater efficiency specs listed in mixed units.
Verify propane or natural gas energy content when switching between kcal and BTU datasheets.
Convert calorimeter output from kcal to BTU for thermodynamics coursework.
Estimate heat output of industrial burners rated in kcal per hour to BTU per hour.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu