Wood CFT Calculator
Enter your board’s dimensions below and this calculator returns the volume in cubic feet (CFT) instantly — plus the equivalent board feet and an optional cost estimate. Give thickness and width in inches and length in feet (the way lumber is usually described), and the results update as you type.
What the CFT calculator does
Lumber gets sold in inconsistent units — sometimes linear feet, sometimes board feet, sometimes cubic feet — and CFT (cubic feet) is the measure you’ll often need when buying logs, slabs, or ordering by volume. This tool takes the three dimensions of a piece of wood and converts them to cubic feet, so you can quote a supplier, compare prices, or size a project without doing the arithmetic by hand.
It also shows board feet, because the two units are directly related and lumberyards frequently price in board feet: one cubic foot of lumber equals 12 board feet. And if you enter a price per cubic foot, it estimates the total cost of your order.
The formula (so you can check the math)
If you’d rather calculate by hand — or verify the tool — here are the exact conversions.
With length in feet (thickness and width in inches):
Cubic feet = (Thickness in × Width in × Length ft) ÷ 144
With all three dimensions in inches:
Cubic feet = (Thickness in × Width in × Length in) ÷ 1728
(There are 1,728 cubic inches in a cubic foot: 12 × 12 × 12.)
To convert to board feet:
Board feet = Cubic feet × 12
To estimate cost:
Total cost = Total cubic feet × Price per cubic foot
Worked example
Say you’re pricing a board 2 inches thick, 6 inches wide, and 8 feet long:
Cubic feet = (2 × 6 × 8) ÷ 144 = 96 ÷ 144 = 0.667 ft³
That single board is 0.667 cubic feet — or 8 board feet (0.667 × 12). If you need ten of them, that’s 6.67 cubic feet total. At a quoted rate of $30 per cubic foot:
Total cost = 6.67 × $30 = $200.10
Those are the same numbers the calculator above returns when you plug them in.
Who this is for
If you work wood professionally, cubic-foot math is probably second nature. This tool is really for beginner woodworkers and DIY homeowners who need to talk volume with a lumber supplier — before placing an order, measure the thickness, width, and length of the stock you need, run it through the calculator, and you’ll know both the cubic feet to order and the ballpark cost.
Planning a build? Pair this with our board foot calculator and lumber calculator for the other units you’ll run into, and once your stock is milled, protect it with the best wood preservatives so the project lasts.
Frequently Asked Questions
What is CFT in wood measurement?
CFT stands for cubic feet — a measure of the volume of a piece of wood, equal to a block one foot long, one foot wide, and one foot thick. It’s commonly used when buying logs, slabs, and lumber sold by volume rather than by the piece.
What’s the difference between cubic feet and board feet?
Both measure lumber volume, but a board foot is a smaller unit — a piece one foot long, one foot wide, and one inch thick. One cubic foot equals 12 board feet. Lumberyards often price in board feet; log and slab sellers often price in cubic feet.
How do I calculate cubic feet if my length is in inches?
Divide by 1,728 instead of 144: Cubic feet = (Thickness × Width × Length) ÷ 1,728, with all three dimensions in inches. The calculator above assumes length in feet, so convert inches to feet first (divide by 12) or use this formula by hand.
Does the calculator account for waste or kerf?
No — it gives the exact volume of the dimensions you enter. For a real project, add roughly 10–15% extra to cover saw kerf, defects, and trimming when you place your order.