# Kilowatt-hours to Kilojoules (kWh to kJ)

> Convert kilowatt-hours to kilojoules: 1 kWh = 3600 kJ. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

- Page id: `kwh-to-kj` · Quantity: Energy (`energy`, base unit J) · Tool: `convert_units`
- Canonical page: https://tttkmbb.com/conversion/kwh-to-kj · This document: https://tttkmbb.com/conversion/kwh-to-kj.md · JSON: https://tttkmbb.com/conversion/kwh-to-kj.json (add `?value=` for a result)

## Formula

- `1 kWh = 3600 kJ`
- `kilojoules = kilowatt-hours × 3600`
- Reverse: `kilowatt-hours = kilojoules × 0.0002777777778`

The factor follows from the SI definitions of both units (NIST SP 811); values below are rounded to 6 significant figures, the API returns up to 12.

## Worked examples

- 5 kWh = 18000 kJ
- 12.5 kWh = 45000 kJ
- 100 kWh = 360000 kJ

## Conversion table

| Kilowatt-hours (kWh) | Kilojoules (kJ) |
| --- | --- |
| 1 | 3600 |
| 2 | 7200 |
| 3 | 10800 |
| 4 | 14400 |
| 5 | 18000 |
| 6 | 21600 |
| 7 | 25200 |
| 8 | 28800 |
| 9 | 32400 |
| 10 | 36000 |
| 15 | 54000 |
| 20 | 72000 |
| 25 | 90000 |
| 30 | 108000 |
| 40 | 144000 |
| 50 | 180000 |
| 75 | 270000 |
| 100 | 360000 |
| 200 | 720000 |
| 250 | 900000 |
| 500 | 1800000 |
| 1000 | 3600000 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=kWh&to_unit=kJ` → unified JSON envelope with `result.values.result`, `formula`, `factor`, `sources`, `freshness`
- MCP: server `https://tttkmbb.com/mcp`, tool `convert_units` with `{"value":5,"from_unit":"kWh","to_unit":"kJ"}`
- All energy units: https://tttkmbb.com/api/v1/units?quantity=energy · full converter: [Energy Converter](https://tttkmbb.com/conversion/energy.md)
- Authentication: none. Freshness: `static` (fixed conversion factors).

## FAQ

**How many kilojoules are in one kilowatt-hour?**

1 kWh = 3600 kJ. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

**What is the formula to convert kilowatt-hours to kilojoules?**

Multiply the value in kilowatt-hours by 3600: kilojoules = kilowatt-hours × 3600. For example, 5 kWh = 18000 kJ.

**How do I convert kilojoules back to kilowatt-hours?**

Multiply by the inverse factor 0.0002777777778 (kilowatt-hours = kilojoules × 0.0002777777778), or use the kilojoules-to-kilowatt-hours page.

## Related conversions

- [Kilojoules to kilowatt-hours](https://tttkmbb.com/conversion/kj-to-kwh.md) (reverse)
- [Kilocalories (food calories) to Kilojoules](https://tttkmbb.com/conversion/kcal-to-kj.md)
- [Kilojoules to Kilocalories (food calories)](https://tttkmbb.com/conversion/kj-to-kcal.md)
- [Joules to Calories (small, thermochemical)](https://tttkmbb.com/conversion/joules-to-calories.md)
- [Calories (small, thermochemical) to Joules](https://tttkmbb.com/conversion/calories-to-joules.md)
- [Kilowatt-hours to Megajoules](https://tttkmbb.com/conversion/kwh-to-mj.md)
- [Megajoules to Kilowatt-hours](https://tttkmbb.com/conversion/mj-to-kwh.md)
- [Kilowatt-hours to BTU](https://tttkmbb.com/conversion/kwh-to-btu.md)
- [BTU to Kilowatt-hours](https://tttkmbb.com/conversion/btu-to-kwh.md)

## Data Sources

- NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors — https://www.nist.gov/pml/special-publication-811 (standard, retrieved 2026-09-24)
- BIPM – The International System of Units (SI Brochure, 9th edition) — https://www.bipm.org/en/publications/si-brochure (standard, retrieved 2026-09-24)
- Wikipedia – Conversion of units — https://en.wikipedia.org/wiki/Conversion_of_units (reference, retrieved 2026-09-24)