Firewood cord calculator: cords and face cords from a stack

A load of firewood always looks bigger heaped in a pickup bed than it does stacked along the garage wall, and that gap is where most firewood arguments start. This gauge settles them with a tape measure. Stack the wood, then measure its length along the row, its height, and its depth from front to back. Stacks are rarely level, so take the height in three or four places and use the average. Finally, enter the length of the pieces themselves, since that decides what a face cord means for your wood.

Choose your units with the two buttons at the top: Feet / inches, or Meters / cm. In metric mode the stack measurements are in meters and the piece length in centimeters. Switching converts whatever is already in the boxes, so the default 8 ft stack becomes 2.44 m and 16 inch pieces become 40.6 cm.

How it works

A full cord is a stack 4 feet high, 4 feet deep and 8 feet long: 128 cubic feet of stacked wood, air gaps included. The gauge multiplies your three measurements to get the volume of the stack and divides by 128 for full cords.

full cords = length × height × depth (in feet) ÷ 128

A face cord is a different animal. It is a stack 4 feet high and 8 feet long but only one row deep, so its volume depends on the pieces: 4 × 8 × (piece length in inches ÷ 12) cubic feet. The gauge divides your stack by that figure for face cords, and also says what share of a full cord one face cord of your pieces makes. In metric mode, it converts meters to feet and centimeters to inches first, then does the same sums.

The readout, titled "Stacked volume", shows full cords as the big figure. A banded scale from 0 to 2 cords sits under it, with three bands: up to half a cord, over half a cord up to a full cord, and more than a full cord. Three lines follow: face cords of this piece length, how much of a full cord one face cord is, and the volume in cubic feet with cubic meters beside it.

Worked example

The gauge opens on a stack 8 feet long, 4 feet high and 4 feet deep, built from 16 inch pieces. That is the textbook cord: 8 × 4 × 4 = 128 cubic feet. The readout shows:

• Stacked volume: 1 full cord, with the marker halfway along the scale in the band for over half a cord, up to a full cord
• Face cords of this piece length: 3
• One face cord is: 33% of a full cord
• Volume: 128 ft³ (3.62 m³)

With 16 inch pieces, a face cord is 4 × 8 × 1.33, or about 42.7 cubic feet, so three rows of them side by side make the full cord. Now measure a single row of the same wood, 8 feet long and 4 feet high, and enter 1.33 feet for the depth. The gauge shows about a third of a full cord and 1 face cord, which is exactly what a seller offering "a face cord of 16 inch wood" should be delivering.

What changes the answer

Piece length. The face cord shrinks and grows with the wood. Cut to 12 inches, one face cord is a quarter of a full cord. At 16 inches it is a third. At 24 inches it is half. If someone quotes a face cord without saying how long the pieces are, the quote is missing half its meaning.

How the wood is stacked. A cord is measured as stacked wood, air and all. Tight, parallel rows hold more wood in the same 128 cubic feet than a loose stack of crooked pieces with big gaps, so a sloppy stack shortchanges the buyer while still measuring a cord on paper. Measure only the stacked rows, and treat crisscrossed end towers with some suspicion, since they hold more air than wood.

Thrown wood. Wood tossed loose into a truck takes up much more room than the same wood stacked, so measuring a heaped truck bed overstates what you have. Stack it first, then measure. Seller terms such as "rick" and "truckload" vary from one place to the next, so ask for the dimensions and the piece length in feet and inches.

Dry wood, clean fires

Volume tells you how much wood you have. Moisture tells you how well it will burn. Seasoned wood reads under 20% moisture on a pin meter: split a piece and press the pins into the fresh face, across the grain, with the wood at room temperature. Without a meter, look for checks in the ends, grey ends, loose bark, lighter weight and a hollow knock when two pieces meet. Most split hardwood needs 6 to 12 months stacked off the ground with the top covered and the sides open to the wind, and oak often takes longer.

Wet wood smolders, which means more smoke in the valley on a still morning, more creosote in the flue and less heat in the room. Our explainer on the Air Quality Index on smoky days covers what that smoke means for the air outside. The same rule holds for a sugaring fire: dry wood keeps an evaporator at a hard boil, and the sap to syrup calculator estimates how many hours of boiling the woodpile has to cover.

Two habits matter as much as dry wood. Have the chimney inspected and swept once a year, and keep carbon monoxide alarms on every level of the house and outside each sleeping area. And buy firewood near where you burn it: logs moved long distances can carry tree-killing pests, one of several small habits on our green tips page.

Sources

• The 128 cubic foot cord, the legal unit for firewood sales in US weights-and-measures law, as set out in the model method-of-sale rules published by the National Institute of Standards and Technology.
• The face cord as one row of a full cord's face, as the term is commonly used in the firewood trade; local usage varies.
• Seasoning times and moisture readings from university extension forestry and firewood guides.

Questions

How many face cords are in a full cord?

It depends on the piece length. With 16 inch pieces, three face cords make a full cord. With 12 inch pieces it takes four, and with 24 inch pieces just two.

Is a rick the same as a face cord?

Often, but not always. "Rick" is a regional word, and what it means depends on who is selling. Ask for the length, height and piece length, put them into the gauge, and you will know what you are paying for.

Should I measure wood in the truck or after it's stacked?

After it's stacked. Loose wood in a truck bed takes up far more room than the same wood in a tight row, so the truck measurement will always flatter the load. A cord is defined as stacked wood.

How do I know the wood is dry enough to burn?

Split a piece and test the fresh face with a pin meter: under 20% moisture counts as seasoned. Without a meter, look for end checks, grey ends, loose bark and a hollow knock. Split hardwood typically needs 6 to 12 months under a top cover, longer for oak.

Can I use this gauge for a round stack or a heaped pile?

Not directly, since it assumes a rectangular stack. Restack the wood in rows, or measure each straight section separately and add the results. Round stacks look lovely but are hard to measure honestly.