EnergyCalories to Kilojoules

Calories to Kilojoules

Methodology·How We Verify

Snapshot

1 Calorie equals 0.004184 Kilojoules.

Reference basis: This conversion uses exact joule-based energy definitions.
Example: For 5 Calories, the result equals 0.02092 Kilojoules.

Interactive conversion

Converter Calculator

Decimals: 1.5 or 1,5. Fractions: 1/2. Scientific notation: 1e3. Write 1000 without grouping separators.

0.004184 Kilojoules (kJ)

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API and AI agent access

Calories to Kilojoules.

Machine-readable identifiers

Conversion family: energy
Source unit: calories
Target unit: kilojoules

Use these identifiers in the API request. Sources and model limits also apply to software clients.

Example API request and response

POST /api/v1/convert

Request

{
  "family": "energy",
  "value": 1,
  "from": "calories",
  "to": "kilojoules"
}

Essential response

{
  "ok": true,
  "conversion": {
    "family": "energy",
    "value": 1,
    "from": "calories",
    "to": "kilojoules",
    "result": {
      "raw": 0.004184,
      "display": "0.004184"
    },
    "canonicalPath": "/energy/calories-to-kilojoules/"
  }
}

API, OpenAPI and WebMCP documentation

Explanation

Multiply by 0.004184 (derived from joules) because 1 cal = 4.184 J and 1 kJ = 1000 J.

Method & Reference

Method basis: exact conversion formula shown in Snapshot.
Applied factor: 1 Calorie = 0.004184 Kilojoules (using exact joule-based energy definitions).
Consistency rule: calculator output and table values use the same constants and rounding policy.

Common Conversion Values

Calories (cal)	Kilojoules (kJ)
1	0.004184
5	0.02092
10	0.04184
100	0.4184
1000	4.184
3600	15.0624
10000	41.84
1000000	4,184

Questions & answers

Frequently Asked Questions

What is 1 calorie in kilojoules?

1 Calorie equals 0.004184 Kilojoules on this page.

When would I convert calories to kilojoules?

This route is useful when translating thermal and nutritional energy values across calories, kilocalories, BTU, and joule-based references without mixing the underlying definitions.

How do I reverse Calories to Kilojoules?

Use the mirror Kilojoules to Calories route; it applies the inverse relationship with the same energy assumptions.