Convert Gigajoules to Watt-Hours

Convert Gigajoules (GJ) to Watt-Hours (Wh) instantly and accurately.

Conversion Formula

Wh = GJ × 277777.7778

About Gigajoules

A gigajoule (GJ) is 10⁹ J - the scale of fossil-fuel commodity volumes. One barrel of crude oil contains ~5.80 GJ; one metric tonne of hard coal ~29.3 GJ. Canadian energy bills express household consumption in GJ: average Canadian households use ~100-130 GJ/year. A 1 GW power plant at 33% efficiency burns ~10.9 GJ/h of fuel to generate 1 GWh = 3.6 GJ of electricity. Detonation of 1 tonne of TNT releases 4.184 GJ. 1 GJ = 10⁹ J = 277.78 kWh = 947,817 BTU = 9.4782 therms.

About Watt-Hours

A watt-hour (Wh) is the energy delivered by 1 watt for one hour - exactly 3,600 J. It is the practical unit for small-scale electrical energy: a 10,000 mAh 5 V power bank stores 50 Wh; a laptop battery holds 50-90 Wh; a smartphone battery holds 10-15 Wh; an AA alkaline cell stores ~3 Wh. LED lamps labelled 9 W save 51 Wh/h over a 60 W incandescent. IATA dangerous-goods rules use Wh as the threshold for lithium batteries in aircraft: cells >20 Wh and batteries >100 Wh need special approval. 1 Wh = 3,600 J = 3.412 BTU.

Quick Reference Table

→ Full Energy Converter