Firewood Calculator

About the Firewood Calculator

This tool helps you estimate how much firewood you need for a heating season and what it will cost. The cords-needed mode combines your usage pattern, season length, home size, and climate into a concrete cord estimate. The cost mode takes that cord count and prices it against wood species and delivery options. Both outputs give you numbers you can use when ordering wood — ideally in late spring, before summer-season prices drop and before green wood can season in time for winter.

Understanding Cords of Firewood

The cord is the standard unit for measuring firewood in North America, and it is also one of the most misunderstood. A full cord is legally defined as 128 cubic feet of wood in a neatly stacked pile: 4 feet wide, 4 feet tall, and 8 feet long. That 128 cubic feet includes wood, bark, and the inevitable air spaces between pieces — the actual solid wood content runs roughly 80 to 90 cubic feet depending on how tightly pieces are stacked and how irregular the splits are.

A face cord — also called a rick or a stove cord in different parts of the country — has the same 4-foot-tall by 8-foot-wide face as a full cord, but the depth is roughly 16 inches (the typical length of a split for a standard wood stove or fireplace insert). Because a full cord is 48 inches deep and a face cord is 16 inches, one full cord equals three face cords. This is where most firewood confusion originates: a seller advertising "a cord" may mean a face cord, cutting the actual volume to one-third of what the buyer expects.

A rick is the same as a face cord in most regions, but usage varies — in some areas a rick is described as any partial cord with no precise depth. The safest approach is always to ask for the measurement in cubic feet or confirm the depth of the stack in inches before agreeing on a price. Most states legally require firewood to be sold by the cord or fraction of a cord, not by vague terms like "truckload" or "pickup load."

Stacking matters more than sellers acknowledge. A loosely tossed pile of wood takes up the same nominal space as a tightly stacked one, but the tightly stacked pile contains significantly more actual wood. When you receive a delivery, stack it yourself and measure the result — a difference of 10 to 20 percent from the claimed volume is common with loose deliveries.

Wood Species and BTU Output

Not all firewood delivers the same heat. The key measurement is BTU per cord — British Thermal Units, the energy required to raise one pound of water one degree Fahrenheit. A cord of dense hardwood can deliver twice the heat of a cord of lightweight softwood, which is why species selection matters as much as quantity.

Hickory leads the field at roughly 26 million BTUs per cord. It burns long and hot, produces excellent coals, and is the preferred wood for smoking meat as well as heating. The trade-off is price: hickory is less widely available than oak and typically costs more. Oak follows at about 24 million BTUs per cord and is the practical benchmark: widely available across North America, burns cleanly, produces long-lasting coals, creates minimal sparking, and is safe for all EPA-certified wood stoves and open fireplaces. Most firewood guides recommend oak as the best all-around choice precisely because it combines high heat output with availability and safety.

Maple runs about 23 million BTUs and is an excellent choice in the Northeast, where sugar maple is abundant. Ash and cherry each produce roughly 20 million BTUs per cord. Cherry is particularly prized for its pleasant smell and moderate density. Apple and fruitwood are dense and fragrant, beloved for fireplaces and outdoor cooking, but rarely sold in quantity — they tend to come from orchard clearing rather than dedicated forestry. Douglas fir is the dominant softwood option in the western United States at about 20 million BTUs; it burns faster than hardwoods of equivalent weight but is a reasonable heating wood when hardwood is scarce or expensive.

Pine and other softwoods typically run 14 to 17 million BTUs per cord. They ignite easily and burn hot initially, which makes them useful for kindling and fire starting, but they burn through quickly and produce more creosote than hardwoods — the resin content that contributes to the pleasant smell also deposits on chimney walls when burned at low temperatures.

Seasoned vs. Green Wood

Moisture content is arguably more important than species. Freshly cut (green) wood contains 40 to 60 percent moisture by weight. When you burn green wood, much of the fire's energy goes toward evaporating that water rather than producing heat. Green wood smokes heavily, is difficult to start, produces less heat per pound, and — most importantly — creates significantly more creosote buildup in your chimney or flue.

Seasoned firewood has been air-dried to 15 to 25 percent moisture content, typically through 6 to 24 months of outdoor stacking. Hardwoods generally need longer than softwoods because their denser cells hold moisture more tightly. A single summer of drying (roughly 5 to 6 months from spring cutting to fall burning) is often not enough for dense oak or hickory — those species benefit from a full year or more.

Kiln-dried firewood is forced-dried in an industrial kiln to below 20 percent moisture, often 10 to 15 percent. It lights easily, burns cleanly, and produces minimal creosote. The trade-off is cost: kiln-dried wood typically runs $350 to $500 per cord, significantly more than air-dried hardwood. It is most practical for occasional use where convenience matters more than price.

How to tell if wood is seasoned: check the end grain for radial cracks (checks) — these form as moisture leaves the wood and are a reliable sign of drying. Knock two pieces together: seasoned wood produces a sharp, hollow clunk; green wood thuds dully. Seasoned wood feels noticeably lighter and the bark peels or detaches more easily. A moisture meter (available for under $30 at hardware stores) is the most reliable check — insert the probes into a freshly split face and aim for readings below 25 percent.

Creosote and Chimney Safety

Creosote is the single biggest safety concern with wood burning. It is a byproduct of incomplete combustion — when wood smoke cools in the flue before fully oxidizing, the condensed vapors and particles coat the chimney liner with a dark, flammable deposit. Burning wet wood or smoldering fires at low temperatures dramatically accelerates creosote buildup.

Creosote comes in three stages. Stage 1 is a light, dusty, flaky deposit that can be brushed out during an annual cleaning. Stage 2 is a thicker, tarry buildup that requires more aggressive mechanical cleaning. Stage 3 is glazed or hardened creosote — the most dangerous form, requiring chemical treatment or, in severe cases, chimney liner replacement. A creosote chimney fire can reach 2,000 degrees Fahrenheit, far exceeding what most liners are designed to withstand, and is a leading cause of house fires in wood-burning households.

The National Fire Protection Association (NFPA) recommends annual chimney inspection and cleaning by a certified chimney sweep, regardless of how much you burn. Most fire codes require it as well. EPA-certified wood stoves, which burn at higher combustion temperatures and leave less unburned smoke, produce substantially less creosote than older, uncertified stoves — and since 2020, EPA certification has been required for new wood stoves sold in the United States.

Buying Firewood

Timing is everything when buying firewood. The best time to buy is late winter through spring, when dealers are clearing inventory and prices are at their lowest. Green wood purchased in April or May can season through the summer and be ready by November — and you get full choice of species and quantity. Buyers who wait until October often pay 20 to 30 percent more and risk receiving freshly cut wood that will not season before they need to burn it.

Always buy by the cord or fraction of a cord, never by "truckload." A standard pickup truck holds about half a cord; a larger truck may hold a full cord — but the only way to know is to stack and measure. Inspect the wood before accepting delivery: look for the end-grain checks that indicate seasoning, smell for the musty or vinegary notes of properly dried wood, and check for uniform split sizes (very irregular pieces may have been mixed with substandard wood).

Sources vary in reliability. Local hardwood dealers who specialize in firewood typically have the best-seasoned product and the most accurate cord measurements. Home improvement stores sell firewood in small bundles at high per-cord prices — convenient but expensive for anything beyond a fire or two. Classified ads (Craigslist, Facebook Marketplace) can offer good prices, especially from orchards or tree services clearing debris, but quality and measurements vary widely.

Wood Stoves vs. Fireplaces

A traditional open masonry fireplace is largely decorative as a heat source. Most of its heat goes up the chimney — efficiency ratings run roughly 10 to 20 percent, meaning 80 to 90 cents of every dollar's worth of wood heat escapes up the flue. The draft a fireplace creates also pulls warm room air out of the house even when the fireplace is not in use, unless a tight damper is installed and closed.

A wood stove is fundamentally different. By enclosing the combustion chamber and using a controlled air supply, a good EPA-certified wood stove achieves 70 to 85 percent efficiency — four to eight times the useful heat output per cord compared to an open fireplace. A fireplace insert is a wood stove installed into an existing fireplace opening, giving older homes much of the efficiency gain without a full rebuild.

For homes where wood is the primary heat source, a high-efficiency insert or freestanding stove is strongly recommended. For supplemental heating and ambiance, even a fireplace can make a meaningful contribution on cold nights — it simply requires more wood to produce the same room heating effect.

Storing Firewood Properly

Proper storage protects your investment and keeps wood drying toward optimal moisture levels. Stack wood off the ground: a commercial firewood rack, wooden pallets, or pressure-treated rails all work. Ground contact allows moisture wicking and speeds rot. Leave the sides of the stack open to air — ventilation is essential for seasoning; trapping moisture inside a fully covered stack defeats the purpose. Cover only the top of the stack with a tarp or purpose-built firewood cover, and make sure the tarp does not hang down over the sides.

Keep stacked firewood at least 30 feet from your house. A woodpile is prime habitat for carpenter ants, termites, mice, and other wood-boring insects that will move from the pile to your home if given the chance. Bring in only a day or two of wood at a time rather than stacking a large indoor supply.

Fire Building Techniques

The top-down fire method has gained wide adoption because it produces significantly less smoke on startup than the traditional bottom-up method. Place your largest logs on the bottom in a grid, add progressively smaller pieces above, then kindling, and top with crumpled newspaper or a fire starter. Light the top — the fire burns downward, and by the time it reaches the main logs the combustion temperature is high enough to burn efficiently with little smoke. Top-down fires are also easier to light on the first attempt because the heat flow is naturally downward into the main fuel.

The traditional bottom-up method (newspaper and kindling on the bottom, logs on top) is equally valid but typically produces more smoke during the startup phase until the logs catch and temperatures rise. Either method works well with properly seasoned wood; neither works well with green wood.

Safety Rules

Never burn treated lumber, plywood, particleboard, cardboard, paper products (other than small amounts of newspaper for starting), painted wood, or pressure-treated wood — these release toxic compounds and in some cases heavy metal fumes into your living space. Use a fireplace spark screen whenever the fire is burning and unattended, and keep rugs, furniture, and combustibles at least three feet from the firebox opening. Allow ashes to cool in the firebox for at least four days before removing them — hot embers can survive for 72 hours under ash — and dispose of them in a metal bucket with a tight-fitting lid, stored away from the house. Install a carbon monoxide detector on every level of your home; wood fires that back-draft can introduce CO even without a full chimney blockage.

Frequently Asked Questions

Wood Species BTU Reference

Moisture Content Reference

Usage Scenarios and Cord Estimates