Horsepower-Hour to Gigajoule Converter

Energy Converter

27 units available

Decimals:

From

To

0.002685

1 hp·h = 0.002685 GJ

Formula:

GJ = hp·h × 0.0026845195

With your value: 1 hp·h = 0.00268452 GJ

How big is that?

Everyday references on a logarithmic scale, all expressed in horsepower-hour so you can sanity-check the result.

Heartbeat (1/2.7e+6 your value)3.73e-7 hp·h

AA battery charge (1/2.7e+2 your value)0.00373 hp·h

Slice of bread (1/9.6 your value)0.104 hp·h

Your value1.00 hp·h

Daily food intake (3.1× your value)3.13 hp·h

Litre of petrol (13× your value)12.7 hp·h

Other Horsepower-Hour to Gigajoule conversions

2 hp·h to GJ 3 hp·h to GJ 4 hp·h to GJ 5 hp·h to GJ 6 hp·h to GJ 7 hp·h to GJ 8 hp·h to GJ

Horsepower-Hour to Gigajoule Conversion Table

Horsepower-Hour (hp·h)	Gigajoule (GJ)
0.5	0.001342
1	0.002685
2	0.005369
5	0.013423
10	0.026845
15	0.040268
20	0.05369
25	0.067113
50	0.134226
100	0.268452
250	0.67113
500	1.34226
1000	2.68452

Gigajoule to Horsepower-Hour Conversion Table

Gigajoule (GJ)	Horsepower-Hour (hp·h)
0.5	186.253068
1	372.506136
2	745.012272
5	1,862.53068
10	3,725.06136
15	5,587.59204
20	7,450.12272
25	9,312.6534
50	18,625.3068
100	37,250.6136
250	93,126.534
500	186,253.067999
1000	372,506.135998

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Horsepower-Hour (hp·h)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Gigajoule (GJ)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Horsepower-Hour to Gigajoule

To convert from Horsepower-Hour (hp·h) to Gigajoule (GJ), multiply the value by 0.0026845195.

Formula: GJ = hp·h × 0.0026845195

Reverse: hp·h = GJ × 372.5061359981

Step-by-Step Example

Start with your value in Horsepower-Hour. For example: 5 hp·h
Multiply by the conversion factor: 5 x 0.0026845195
The result is: 0.013423 GJ

About Horsepower-Hour

The horsepower-hour (hp·h) is a unit of energy and work. One horsepower-hour equals 2.684520 × 10^+6 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

About Gigajoule

The gigajoule (GJ) is a unit of energy and work. One gigajoule equals 1.000000 × 10^+9 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

Frequently Asked Questions

How many Gigajoule are in 1 Horsepower-Hour?

There are exactly 0.0026845195 Gigajoule in 1 Horsepower-Hour. This means the conversion factor from Horsepower-Hour to Gigajoule is 0.0026845195.

What is the formula to convert Horsepower-Hour to Gigajoule?

The formula to convert Horsepower-Hour to Gigajoule is: GJ = hp·h × 0.0026845195. For example, to convert 10 Horsepower-Hour to Gigajoule, you would multiply 10 by 0.0026845195.

What is a Horsepower-Hour?