Which firewood has the most BTU?

In Penn State Extension's table, Osage orange is highest at 30.7 million BTU per air-dried cord, followed by hickory (28.0), ironwood/hop hornbeam (27.3), hornbeam and black birch (26.8), honey locust (26.7) and the white oak group (25.7). Red and silver maple are lowest at 18.7.

How many BTU are in a cord of oak?

About 24.0 million BTU for the red oak group and 25.7 million BTU for the white oak group per full cord (128 cubic feet stacked) at about 20% moisture. At 75% stove efficiency that is roughly 18–19 million BTU of usable heat.

How much heat does wet firewood lose?

Every pound of water must be heated, boiled and carried up the flue, which takes about 1,200 BTU. A cord of red oak at 20% moisture holds roughly 560 lb of water; at 50% it holds about 1,400 lb, so the extra 840 lb costs about 1.0 million BTU before counting the lower combustion efficiency, smoke and creosote that wet wood also causes. That is why the tool calls its figure a minimum loss.

How much is a face cord?

A face cord (or rick) is a stack 4 ft high and 8 ft long, one piece deep. With 16-inch pieces it holds 42.7 cubic feet, one third of a full cord; with 12-inch pieces it is one quarter, and with 24-inch pieces one half. Use the stack converter to turn any stack into full cords.

Is firewood cheaper than propane or heating oil?

Usually, if you can buy or cut seasoned wood at a typical price. Example: red oak at $300 per cord in a 75% efficient stove costs $16.67 per usable million BTU. Propane at $2.60 per gallon in a 90% furnace costs $31.59, heating oil at $3.80 in an 85% boiler costs $32.28, and natural gas at $1.50 per therm in a 95% furnace costs $15.79. Enter your own prices in the comparison table.

Why can other firewood charts show different values?

Charts use different methods, moisture bases and individual trees. Some list oven-dry heat, some air-dried, and some use a heavier assumed cord. This page keeps every species on the same cited Penn State basis instead of mixing sources.

Firewood BTU Reference Chart & Heating Estimator

Penn State Extension rates air-dried (20% moisture) hardwood from 18.7 million BTU per cord (red and silver maple) to 30.7 (Osage orange); oak is 24–25.7. Estimate usable heat after stove efficiency, the extra loss from wetter wood, heating hours, and cost per million BTU against heating oil, propane, natural gas, electricity and pellets.

Firewood Heat Value by Species

Penn State Extension Table 1 · Air-dried basis (~20% moisture)

Firewood species heat content in million BTUs per full cord
Species	Botanical Name	MMBTU / Cord	vs Red Oak
Osage orange	Maclura pomifera	30.7	128%
Hickory—shagbark, bitternut, mockernut, and pignut	Carya ovata, cordiformis, tomentosa, and glabra	28.0	117%
Ironwood/hop hornbeam	Ostrya virginiana	27.3	114%
Hornbeam/blue beech	Carpinus caroliniana	26.8	112%
Black birch	Betula lenta	26.8	112%
Honey locust	Gleditsia triacanthos	26.7	111%
White oak group	Quercus spp.	25.7	107%
Sugar maple	Acer saccharum	24.0	100%
Red oak group	Quercus spp.	24.0	100%
White ash	Fraxinus americana	23.6	98%
Yellow birch	Betula alleghaniensis	23.6	98%
Hackberry	Celtis occidentalis	20.8	87%
Birch—paper, gray, and river	Betula papyrifera, populifolia, and nigra	20.3	85%
Black walnut	Juglans nigra	20.2	84%
Black cherry	Prunus serotina	19.9	83%
Maple—red and silver	Acer rubrum and saccharinum	18.7	78%

Primary source: Penn State Extension, Heating with Wood: An Introduction (Table 1). Values are MMBTU per full cord of air-dried wood at about 20% moisture content.

Botanical names: spelling errors in the source table (Ostryq, Betlua) are corrected, and hornbeam/blue beech is listed as Carpinus caroliniana rather than the source's Ostrya.

Full cord vs face cord

A full cord is 128 cu ft stacked (4 × 4 × 8 ft). A face cord or rick is 4 ft high × 8 ft long but only one piece deep, so its size depends on the piece length.

Stack (4 × 8 ft face)	Cu ft	Full cords	Red oak MMBTU
12-inch pieces	32.0	0.250	6.0
16-inch pieces	42.7	0.333	8.0
18-inch pieces	48.0	0.375	9.0
24-inch pieces	64.0	0.500	12.0
Full cord (48 in deep)	128.0	1.000	24.0

Method and limits

Usable heat = MMBTU per cord × cords × efficiency − moisture penalty. Appliance efficiency ratings are measured with seasoned wood, so the table value and your efficiency already assume about 20% moisture.

Moisture penalty. Oven-dry wood mass is taken as gross heat ÷ 8,600 BTU per lb (the usual hardwood heating value). Water = dry mass × meter reading (dry basis). Each extra pound of water above the 20% level costs about 1,200 BTU: 152 to warm it from 60 °F to 212 °F, 970 to boil it and about 90 to carry the steam out at a 400 °F flue. This is a physical minimum; wet wood also burns cooler and less completely.

Worked example. 2 cords of red oak = 48.0 MMBTU gross. At 75% efficiency that is 36.0 MMBTU usable, or 720 hours at 50,000 BTU/hr. Implied dry wood is 48,000,000 ÷ 8,600 = 5,581 lb. At a 35% meter reading the stack holds 1,953 lb of water instead of 1,116 lb, so the extra 837 lb costs at least 1.0 MMBTU, leaving 35.0 MMBTU (700 hours).

Heating hours assume a steady load; real homes cycle with outdoor temperature and thermostat setpoints.

Heating & Fuel Cost Estimator

Usable heat, wet-wood loss, hours and cost per million BTU

Species

Full Cords

128 cu ft each

Efficiency (%)

Fireplace 10–20, EPA stove 70–80

Convert a stack or face cord to full cords

Length (ft)

Height (ft)

Pieces (in)

Moisture (%)

Meter reading, dry basis

Price / Cord ($)

For cost per MMBTU

Continuous heat demand (BTU/hr)

Firewood vs other heating fuels

Edit the example prices and efficiencies to match your area. Cost per usable MMBTU = price ÷ (BTU per unit × efficiency) × 1,000,000. The firewood row uses the species, efficiency, moisture and price from the estimator.

Fuel	BTU per unit	Price ($/unit)	Efficiency %	$ / usable MMBTU	Units = your wood
Firewood (this estimate)	—	—	—	—	—
Heating oil (No. 2)	138,500 / gal			32.28	—
Propane	91,452 / gal			31.59	—
Natural gas	100,000 / therm			15.79	—
Electric resistance	3,412 / kWh			49.82	—
Heat pump (COP 3)	3,412 / kWh			16.61	—
Wood pellets	16,400,000 / ton			25.15	—

Heat contents: U.S. EIA (heating oil 138,500 BTU/gal, propane 91,452 BTU/gal, natural gas 100,000 BTU/therm, electricity 3,412 BTU/kWh); pellets about 8,200 BTU/lb. Example prices are rough U.S. residential levels, not quotes.

Summary

Heat output varies with species, individual trees, moisture and measurement method. This reference keeps one consistent Penn State Extension table of million BTU per full cord at about 20% moisture, then estimates usable heat after appliance efficiency, the extra evaporation loss when wood is wetter than 20%, operating hours, and fuel cost per delivered million BTU next to other heating fuels using EIA heat contents.

How it works

Search or sort the species chart by name or by million BTU (MMBTU) per full cord.
Pick a species, enter full cords (or convert a stack from length × height × piece length), and your stove or furnace efficiency.
Enter the moisture-meter reading; wood wetter than 20% loses about 1,200 BTU for every extra pound of water it has to boil off.
Enter a continuous heat demand to see how many hours the wood lasts, and a price per cord for cost per usable MMBTU.
Compare the wood cost with heating oil, propane, natural gas, electric resistance, a heat pump and pellets at your local prices.

Use cases

Compare heat per cord across firewood species on the same 20% moisture basis.
Decide whether a cheaper, lower-BTU species is actually a better buy per million BTU.
See how much heat you lose by burning unseasoned wood.
Convert a face cord or rick of 16-inch splits to a fraction of a full cord before pricing.
Compare firewood with propane, heating oil, natural gas, electricity and pellets.
Estimate how long a woodpile lasts at a given heat load.

Frequently Asked Questions

Last updated: 2026-10-10 · Reviewed by Nham Vu