Linear Foot Calculator
Choose a method below. You can calculate linear footage from individual pieces, or convert square footage to linear feet when you know material width.
What is a linear foot?
A linear foot is simply a measurement of length equal to 12 inches. Unlike square footage, it does not include width or thickness. If you place a tape measure along a board, baseboard, fence rail, or countertop edge, the distance you read is linear feet.
People often use linear feet for projects where material is sold by length, including lumber, trim, molding, fencing, wiring, piping, and shipping dimensions.
When to use a linear foot calculator
A linear foot calculator helps prevent underbuying or overbuying materials. It is especially useful when you have many repeated cuts or when converting area into running length for a fixed-width product.
- Trim and molding: Add up wall lengths to estimate baseboard or crown molding.
- Decking and fencing: Estimate rail lengths and board runs.
- Floor transitions: Calculate threshold and transition strip lengths.
- Fabric and flooring rolls: Convert square footage into linear feet based on roll width.
- Freight and storage: Estimate how much trailer or shelf run you need.
How the calculator works
1) Pieces × Length method
Use this when all pieces are the same length, or when you can group similar pieces. Enter quantity and the length of each piece (feet and optional inches). The calculator multiplies piece length by quantity to give total linear feet.
2) Square Feet ÷ Width method
Use this when coverage is known in square feet and material width is fixed (like planks, fabric, or paper rolls). The tool converts area into running length:
Linear feet = (Area in sq ft × 12) ÷ Width in inches
Practical examples
Example A: Baseboard estimate
You need 18 pieces, each 10 feet long. Total linear feet is:
18 × 10 = 180 linear feet
Example B: Mixed feet and inches
You need 24 pieces at 8 feet 6 inches each. Convert inches to feet first:
8 ft 6 in = 8.5 ft, so:
24 × 8.5 = 204 linear feet
Example C: Converting area to linear feet
You have 320 square feet to cover with 6-inch-wide material:
(320 × 12) ÷ 6 = 640 linear feet
Common mistakes to avoid
- Confusing linear feet with square feet: linear feet measure length only.
- Forgetting unit conversion: inches must be divided by 12 to become feet.
- Ignoring waste: add 5–15% extra material for cuts, defects, and installation loss.
- Rounding too early: keep decimals until final purchase quantity.
- Skipping opening deductions: for trim projects, subtract doors or windows if appropriate.
Buying tips for better material planning
Once you compute total linear feet, convert to stock sizes sold by suppliers. For example, if trim is sold in 8-foot and 12-foot sticks, try a cut plan that minimizes offcuts. It can reduce both cost and waste.
For renovation projects, buying a small overage is usually safer than a perfect exact quantity. Matching dye lots, wood grain, or profile style can be difficult later.
Linear feet vs. board feet (quick clarification)
Linear feet and board feet are different. Board feet include thickness and width of lumber:
Board feet = (Thickness in inches × Width in inches × Length in feet) ÷ 12
If you only need run length, use linear feet. If pricing is based on lumber volume, use board feet.
Final thoughts
A reliable linear foot estimate is one of the easiest ways to control project budget and reduce jobsite delays. Use the calculator above, add a sensible waste factor, and map your cuts before you buy. A few minutes of planning can save hours later.