English oak firewood: BTU, weight and seasoning

Heat per cord

English oak is a hardwood. At 20% moisture, a full cord holds about 24.6 million BTU of heat (26.0 gigajoules). Wetter wood gives less, because part of the heat goes into boiling off the water.

That ranks English oak 305th of the 558 species in our tables, from the hottest down.

Weight and density

A full cord of seasoned English oak (20% moisture) weighs about 4,000 lb (1,820 kg). Freshly cut, the same cord weighs about 4,800 lb (2,180 kg): the difference is water you don't want to burn.

Its specific gravity, a measure of density, is 0.67. Denser wood packs more heat into each cord.

Seasoning time

Split and stacked off the ground, English oak needs at least 10 months to dry to about 20% moisture.

Wood dries faster once it is split and stacked with air around it. A moisture meter on a fresh split face tells you when it is ready.

How it burns

• Ash: low
• Coals: high
• Burn time: long

We rate English oak 5 out of 10 as firewood: a good choice.

Similar firewood

Other species to compare with English oak:

• Black oak: 26.1 million BTU per cord
• Bur oak: 26.4 million BTU per cord
• California black oak: 22.6 million BTU per cord
• Cherrybark oak: 28.6 million BTU per cord

Where these numbers come from

The heat and weight figures come from our firewood tables, worked out the same way for every species at 20% moisture. See how we calculate them.

Questions