Energy conversion

Calories to Kilojoules (kJ) conversion

Convert calories (cal) to kilojoules (kJ). Thermochemical: 1 cal ≈ 0.004184 kJ. Clarifies food Calorie vs small calorie. Runs locally in your browser.

Instant result

Result

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Enter values to convert.

Inputs —

Mode —

Formula —

Formulas

Core equations used by this converter.

cal → kJkJ = cal × 0.004184

Exact factor1 cal = 0.004184 kJ

kJ → calcal = kJ × 239.00574

iLinear conversion using factor 0.004184. Prefer the exact factor over rounded multipliers when precision matters.

How to use

Choose cal → kJ or kJ → cal

Use the tabs to switch direction. Forward mode needs calories; reverse uses the opposite unit.

Enter the value

Type a non-negative value in the active unit field.

Convert and read the result

Use Convert or let the result update automatically.

Example conversions

Common values with formula and result.

100 cal to kJ

100 × 0.004184 = 0.4184 kJ

0.4184 kJ

1000 cal (= 1 kcal) to kJ

1000 × 0.004184 = 4.184 kJ

4.184 kJ

500 kcal (food) to kJ

500 × 4.184 = 2092 kJ

2092 kJ

Reverse: 4.184 kJ → cal

4.184 / 0.004184 = 1000 cal

1000 cal

Calories to Kilojoules (kJ) conversion specification

Version 1.1.0 · Engine tested

Calculation status

Engine tested 4 published cases
Named expert review Not performed
Calculation version 1.1.0

Review policy

Definition: Calories (cal) converts to kJ using a fixed linear factor. Convert calories (cal) to kilojoules (kJ). Thermochemical: 1 cal ≈ 0.004184 kJ. Clarifies food Calorie vs small calorie.
What it calculates: Value between cal and kJ. Switch direction with the converter tabs.
Inputs: Calories (cal) or reverse unit (kJ)
Outputs: Converted value in kJ or cal
Formula: kJ = cal × 0.004184 · 1 cal = 0.004184 kJ
Calories to kilojoules conversion table: Calories (cal) Kilojoules (kJ)
1 cal 0.004184 kJ
10 cal 0.04184 kJ
100 cal 0.4184 kJ
500 cal 2.092 kJ
1000 cal 4.184 kJ
2000 cal 8.368 kJ
5000 cal 20.92 kJ
Assumptions: Conversion runs locally in the browser; values are not uploaded.
Uses the standard factor/definition for these units.
Units: cal → kJ
kJ → cal
Boundary conditions: Empty or non-numeric input yields no valid result.
Non-negative values are expected for physical quantities.
Example: 1 cal → 0.004184 kJ
Validation cases: 1 cal → 0.004184 kJ
10 cal → 0.04184 kJ
50 cal → 0.2092 kJ
100 cal → 0.4184 kJ
Sources: SI / international unit definitions where applicable
CalculatorX conversion factors (local runtime)
Calculation version: 1.1.0

Calories (cal)	Kilojoules (kJ)
1 cal	0.004184 kJ
10 cal	0.04184 kJ
100 cal	0.4184 kJ
500 cal	2.092 kJ
1000 cal	4.184 kJ
2000 cal	8.368 kJ
5000 cal	20.92 kJ

Background

Interpretation and common distinctions.

Use the converter tabs to switch direction when available. Results for Calories to Kilojoules (kJ) conversion update locally in your browser.

Frequently asked questions

Key distinctions behind the conversion.

How do you convert using Calories to Kilojoules (kJ) conversion?

Use 1 cal = 0.004184 kJ. Example: 100 cal to kJ → 0.4184 kJ.

Can I switch direction?

Use the converter tabs when available, or open the related reverse tool from Related.

Does this run online or locally?

Calculation runs locally in your browser. Values are not uploaded.

How precise are the results?

Results follow the formulas on this page. Round to the precision your use case needs.