Stacks of seasoned firewood can look identical from the road and still hold very different amounts of heat. The species decides how much heat is in the stack; the split size decides how well that heat works in your stove, insert, boiler, fireplace, or firepit.

A cord is a cord by volume — 128 cubic feet of stacked wood, commonly a stack 4 feet high, 4 feet deep, and 8 feet long. But a cord is not a cord by heat. Dense hardwood packs far more burnable material into that same stack than light softwood does, so one cord can hold close to twice the heat of another. This guide ranks common species by expected heat per cord, shows how to compare what you are really paying for, and then matches split size to the job.

One condition applies to every number below: the wood has to be seasoned. At Premium Firewood Supply, seasoned means 20% moisture or less. Seasoned wood burns cleaner than green wood and builds up less creosote, which lowers chimney-fire risk — an important point for newer catalytic and secondary-combustion (burn-tube) stoves. Wet wood spends part of its heat boiling off water instead of heating your home, so a green cord of oak can easily deliver less usable heat than a dry cord of a lower-ranked species.

What BTU per cord means

BTU stands for British Thermal Unit, a standard measure of heat. The figures in this guide are the approximate total heat in one seasoned cord of each species, in millions of BTU. No stove captures every BTU — appliance efficiency decides how much of that heat ends up in the room — but because the same stove burns whatever you load into it, BTU per cord is the fairest way to compare one species against another.

Density is the reason for the spread. Pound for pound, dry wood of almost any species holds a similar amount of heat. A cord, though, is measured by volume, not weight — and a cord of dense oak or hickory simply weighs a great deal more than a cord of pine or cedar. More pounds in the stack means more heat in the stack.

Hardwoods — heat per cord

Hardwoods come from deciduous trees — the leaf trees such as oak, maple, and hickory. They are the heating woods: slower to light than softwood, but longer-burning, with a stronger coal bed that carries heat between loadings.

Softwoods — heat per cord

Softwoods come from evergreens — pine, fir, spruce, and cedar. They hold less heat per cord, but that does not make them poor firewood. They light easily, burn fast and bright, and are ideal for kindling, quick evening fires, shoulder-season heat on mild days, and outdoor fires where a long coal bed matters less.

BTU figures are approximate and match the figures in our Wood Types Guide. Actual heat varies with moisture content, how tightly the cord is stacked, and the individual tree.

The practical difference: cords, loads, and price

The gap between the top and the middle of the tables is bigger than it looks on paper. A cord of Osage Orange at 32.9 million BTU holds about as much heat as roughly two cords of White Pine — and about 2.7 times the heat of a cord of White Cedar at 12.2 million BTU. Put it in heating-season terms: a home that needs about 100 million BTU of wood heat over a winter would burn roughly 3.4 cords of White Oak, but about 7 cords of Balsam Fir to get the same heat. That is twice the stacking, twice the handling, and roughly twice as many trips to the woodpile — and with fast-burning softwood, more and smaller loadings in between.

The same math is the honest way to compare prices. Do not compare price per cord alone; compare price per million BTU. Divide the price of the cord by its BTU figure and you have the cost of one million BTU of heat. For example — using example prices only — a cord of White Oak at $375 works out to about $12.89 per million BTU ($375 ÷ 29.1), while a cord of Douglas Fir at $275 works out to about $15.19 per million BTU ($275 ÷ 18.1). The cheaper cord costs more per unit of heat. Run the same division on any two quotes before you buy and the better value shows itself.

• Compare the species first — heat per cord is the number that matters — two stacks the same size can hold very different amounts of heat.

• Do the division — divide the price by the BTU figure to get the cost per million BTU.

• Count the work — lower-BTU wood has to be stacked, carried, and loaded about twice as often for the same heat.

• Mix on purpose — softwood earns its place for kindling, fast fires, and mild days — it is the long overnight burn where hardwood pulls away.

Split size by use

Split size in this guide means the thickness of the piece — the measurement across its widest split face. Length is a separate question, and the rule for length never changes: the piece must fit your firebox with room to spare, so check your owner's manual before you order or split a season's worth. A piece that is the right thickness but an inch too long is the wrong size.

*Typical lengths only — firebox dimensions vary by model. Measure yours and check the manual before ordering.

• Outdoor wood boiler — its firebox is built for volume, not finesse. Large splits — and in many boilers, large rounds — mean a full load burns for hours between fillings, which is the whole point of the appliance.

• Fireplace insert — an insert is a stove inside a fireplace, with a stove-sized firebox. Medium splits in the 4–6 inch range light reliably, pack in tight enough for a full load, and leave the airflow an efficient burn needs.

• Small wood stove — small stoves have small fireboxes, and oversized pieces are the most common frustration: they will not fit, will not pack, and starve the fire of air. Splits in the 3–5 inch range, cut to your firebox length, are the right call.

• Open fireplace — an open fireplace trades efficiency for atmosphere, and larger splits suit it: they burn longer and steadier, throw a better coal bed, and keep you from feeding the fire every twenty minutes.

• Outdoor firepit — a firepit is the most forgiving of all. A mix works best — smaller, drier pieces to get the fire established, then larger splits on top for a fire that lasts the evening.

Small splits vs. large splits

Neither size is better in the abstract. They do opposite jobs, and most households are happiest with a stack that holds both — small splits for starting and quick heat, large splits for the long burn.

Small splits — advantages

• Light easily — they catch quickly and get a cold stove or a new fire producing heat fast.

• Dry faster — more exposed surface means small splits season faster and reach 20% moisture sooner.

• Fit small fireboxes — they are the only size that loads properly into inserts and small stoves.

• Easier handling — light pieces are simpler to carry in an armload at a time.

• Fast, controllable heat — ideal for kindling, restarting a fire from coals, and quick morning or evening heat.

Small splits — disadvantages

• Burn out quickly — the same surface area that lights fast also burns fast. Expect to reload more often.

• Poor overnight burn — a full load of small splits rarely carries a stove through the night.

• More pieces, more work — a cord of small splits is many more pieces to split, stack, carry, and load than a cord of large ones.

• Can overfire — packed in tightly all at once, small dry splits can burn hotter and faster than a small stove should be run.

Large splits — advantages

• Long burn — dense pieces burn for hours and leave the deep coal bed that makes the next loading easy.

• Overnight heat — large hardwood splits are how a stove holds heat until morning.

• Less handling — fewer pieces per cord at every step — splitting, stacking, carrying, and loading.

• Steady output — a fire built on large splits settles into an even, predictable burn instead of flaring and fading.

Large splits — disadvantages

• Dry slowly — thick pieces take considerably longer to season. Split large wood earlier and give it the time.

• Hard to light — a large split on a cold firebox is hard to get going; large splits belong on an established fire.

• Will not fit — they simply will not load into a small stove or a small insert, whatever the species.

• Heavy to handle — big green or partly seasoned pieces are heavy, and a steady diet of them is real work.

• Can smolder if damp — one large, not-quite-dry piece can smolder instead of burning clean — another reason moisture matters more as splits get bigger.

Putting it together

Choose the species for the heat job and the split size for the appliance. Dense hardwood — oak, hickory, locust, maple — in splits sized to your firebox is the combination that heats a home with the fewest cords and the fewest loadings. Softwood and smaller splits earn their place alongside it for kindling, quick fires, and mild days. And whatever the species or the size, burn it seasoned: at 20% moisture or less, every cord on these tables delivers the heat it promises.

Questions about which species or split size fits your stove, insert, boiler, fireplace, or firepit? We are glad to help you work it out before you buy.

Call or text (336) 486-0313 or visit premiumfirewoodsupplyllc.com.