Locust Firewood Cost Calculator

Multiply your local seasoned oak price by 1.12. That's what a cord of black locust is worth in heat. Below that number it's a deal; above it, buy the oak.

Every other locust page says "high BTU" and stops. Here's the number that decision actually turns on.

Black locust carries about 26.8 million BTU per cord. Red oak carries about 24 million. Divide: 26.8 / 24.0 = 1.12. One cord of locust replaces 1.12 cords of oak in your stove.

That ratio is your fair-price test. If seasoned oak is $300 in your area, locust is fairly priced at $300 x 1.12, or $336.

Quoted $280? That's a deal. Quoted $420? You're paying a premium for the reputation, not the heat.

The mechanism is density. Locust runs a specific gravity near 0.69 against red oak's 0.60, and heat per cord tracks dry wood mass almost linearly. Species heating values come from the USDA Forest Products Lab Wood Handbook, the standard federal reference for wood.

Adjust the number of cords above. Every cord of locust you swap in for oak buys you about 12% more heat for the same stack space, which is why locust households reload less overnight.

Running the same math across birch, ash and hickory before you commit? The firewood BTU calculator does the per-species heat math, and the oak firewood cost calculator gives you the oak baseline number to multiply.

Seasoned black locust runs $200-$420 per cord nationally. Green locust runs $80-$180. Our sourced heat-content benchmark puts locust at $8–$16 per million BTU, which is the figure the state table above adjusts.

The Fence-Post Premium. Black locust is the most rot-resistant native wood in North America, better than treated lumber in ground contact. In farming regions of the Midwest and Appalachia, it gets cut for fence posts first and firewood second.

That competition is real money. Where post demand is strong, locust firewood is scarce and prices sit $50-$100 above the national range. Where locust is treated as an invasive nuisance, in the Northeast and much of Appalachia, sellers move it $20-$40 below oak because they don't know the BTU story.

So the same species sits on both sides of the oak price line depending on what the local farm economy wants from it. Check the state table above before you decide your quote is unfair.

Against our own interest: if you live somewhere locust is scarce and priced at post premium, skip it. Oak at $280 beats locust at $450 on heat per dollar every time, and the calculator will show you that in one keystroke.

This is the part no calculator page tells you. Black locust (Robinia pseudoacacia) is classified invasive across New York, Pennsylvania, New Jersey, Connecticut, most of Appalachia, and Oregon and Washington. It resprouts aggressively, so landowners pay to have it gone.

The wood from those removals is usually free to whoever hauls it. At $0 per cord, the heat-per-dollar math stops being a comparison and becomes a rout.

Branch 1: you own a truck and a chainsaw. Call your county extension office and your state DNR invasive species program. Ask what's scheduled for removal this season. Cost to you is fuel and a weekend.

Branch 2: no truck, no splitter. Truck rental plus a splitter rental day runs roughly $250-$280 all in. Against a $325 seasoned cord you're barely ahead on one cord, and far ahead on three, because the rental is a fixed cost you spread across the load.

Branch 3: Northeast or Appalachia. Search Nextdoor and Facebook Marketplace for "black locust free" or "tree removal free wood." Utility right-of-way crews drop full trunks and want them gone that week.

Set the cord price above to 0 and enter your haul and rental costs as the delivery figure. That's the honest pricing of free locust, and it's usually still the cheapest cord you'll burn.

Timing matters. Removal programs run March through June. A call in spring supplies next winter; a call in October gets you a waiting list.

The density that makes locust burn hot is the same density that makes it dry slowly. Its bark sits tight against the wood and holds moisture in.

Plan on 18 months, and 24 if you can wait. Twelve is the floor only for wood split small and stacked in full sun and wind. Target moisture is under 20%, measured, not guessed.

Burning green locust is expensive in a way most buyers never see on a receipt. Water in the wood absorbs heat as it boils off instead of heating your house, so a load at 35% moisture delivers a fraction of the heat of the same load at 18%.

The rest goes up the flue as steam and unburned smoke, which condenses into creosote in your chimney.

Put a number on it. On a 3 cord season at $325 a cord, that's $975 of wood. Burn it green and you lose the heat equivalent of roughly a cord, close to $325, plus a chimney that needs sweeping sooner.

Split it the week it's cut. Splitting is what breaks the bark seal and lets the core dry. A round left whole for a year is still wet in the middle.

Check at 6, 12 and 18 months with a moisture meter. The EIA wood energy overview explains why moisture content drives usable heat output more than species does at the extremes.

You bought green locust to save $150 a cord. Then you swung a maul at it for an hour and got nowhere. That's not you; it's the grain.

The 10-Ton Rule: green locust needs a hydraulic splitter rated 10 tons or more. Under that, or with a hand maul, you're fighting a stringy interlocked fiber that closes back around the wedge.

Chainsaw work is fine. Locust cuts cleanly across the grain. It's splitting along the grain where the fibers behave more like rope than like oak's clean radial checks.

If you have no splitter, there's a workaround: let the rounds sit 3 to 4 months first. Partial drying opens surface checks that show you where the piece wants to break, and a maul follows those lines.

You lose a little drying time on the whole round, and you gain a season of not hating your firewood.

Dry locust splits cleanly. The reputation for being impossible comes almost entirely from people meeting it green.

Two different trees, one word on the invoice. Black locust holds about 26.8 million BTU per cord. Honey locust holds roughly 21 million. That's a 28% heat deficit at the same price.

Sellers mislabel constantly, and usually not on purpose. Here's the 30 second check.

Black locust: thorns come in pairs, and only at the leaf nodes. Bark is deeply furrowed, gray-brown, with rope-like ridges. Compound leaves with rounded leaflets.

Honey locust: thorns run along the trunk and branches, often branched into clusters, sometimes several inches long. Seed pods are long and twisted, up to a foot.

The shortcut: if thorns appear anywhere except leaf nodes, it isn't black locust. Weight is the backup check. Black locust is heavy for its size. If a claimed locust round feels close to pine, walk.

Ask the seller for the species name out loud before money changes hands. Someone who says "locust" and can't say which one is guessing.

Ask this first: "When did you cut this?" A locust seller who knows the wood answers instantly with a season and a year. "Last spring" means green, whatever the ad said. 18 or more months from cut is the only claim worth the seasoned premium.

Thrown piles measure bigger than they are. A full cord is 128 cubic feet stacked, 4 ft by 4 ft by 8 ft. Unstacked wood always looks like more. With locust the scam is easier to run because the wood is heavy, and lifting a piece makes buyers assume the load is full.

An unusually low price is a moisture disclosure. Seasoned locust is worth a premium; green locust needs two years of your patience. A price well under the local seasoned range almost always means green wood.

A seller who says nothing about splitting doesn't know the species. Anyone who has actually handled locust brings up the density unprompted.

If the cut date comes back under 18 months, drop the cord price above to the green range of $80-$180 and see whether the season still pencils out. Green at the right price is a fine deal; green at seasoned prices is not.

One more line item to price separately: many sellers fold hauling costs into the cord price without saying so. The firewood delivery cost calculator shows what the trip alone should cost so you can tell wood price from freight.

Step 1. Search your county. Type "[your county] invasive species removal program" and "[your state] black locust control." Extension offices publish removal schedules and contractor lists.

Step 2. Call, don't email. Ask: "Do you have black locust removals scheduled this season, and does anyone take the wood?" Land managers want the material gone and rarely have a plan for it.

Step 3. Work the local boards. Search Nextdoor and Facebook Marketplace for "black locust free," "free firewood," and "tree removal wood." Utility right-of-way crews and arborists post drops the same week they cut.

Step 4. Verify the species before you load. Use the thorn check above. Paired thorns at leaf nodes only means black locust.

Thorns along the trunk means honey locust, and about 21 million BTU per cord instead of 26.8.

Bring a chainsaw, straps, and more time than you think. A full trunk is heavier than it looks, and locust rounds are among the densest you'll lift.

Then plan the seasoning from cut date, not delivery date. Free wood you burn green costs you the same lost heat as wood you paid for.