Linear Feet Calculator 2026 | Convert Linear Feet to Square Feet & Board Feet
Calculate linear feet for lumber, flooring, fencing, crown molding, gutters, and baseboards. Add multiple segments, convert to square feet (with width), compute board feet (with thickness), and add a waste percentage — all in one free tool.
Add one or more segments to calculate total linear footage:
Your Linear Footage Results
Based on your segments
What Is a Linear Foot?
A linear foot (also called a lineal foot, abbreviated LF or lf) is simply a measurement of length — one foot (12 inches) in a straight line. Unlike square feet (which measure area — length × width) or cubic feet (volume — length × width × height), a linear foot is a single dimension.
Linear feet are used when you're ordering materials that are sold by the running length, regardless of width or depth. Common examples:
- Lumber: 2×4s, 2×6s, fence rails, and dimensional lumber are all sold by the linear foot or by standard lengths (8, 10, 12 ft).
- Flooring: Hardwood strip flooring and engineered wood planks are often priced per linear foot.
- Fencing: "I need 200 linear feet of fence" means a 200-foot perimeter, regardless of post height.
- Molding & Trim: Baseboards, crown molding, chair rail, and casing are all measured and sold in linear feet.
- Gutters & Downspouts: Priced per linear foot of gutter run.
- Countertops: Some countertops (especially laminate) are priced per linear foot at a standard 25" depth.
How to Convert Linear Feet to Square Feet
To convert linear feet to square feet, you need to know the width of the material:
| Material | Width | 100 LF → Sq Ft | Notes |
|---|---|---|---|
| 2×4 lumber | 3.5" | 29.2 sq ft | Actual width 3.5", nominal 4" |
| 2×6 lumber | 5.5" | 45.8 sq ft | Actual width 5.5" |
| 2×12 lumber | 11.25" | 93.8 sq ft | Common for shelving |
| 3" strip flooring | 3" | 25.0 sq ft | Standard hardwood width |
| 5" plank flooring | 5" | 41.7 sq ft | Wide plank |
| 6" fence boards | 5.5" | 45.8 sq ft | Dog-ear fence picket |
| Laminate countertop | 25" | 208.3 sq ft | Standard depth with backsplash |
Linear Feet to Board Feet — Lumber Calculation
Board feet measure the volume of lumber — accounting for length, width, and thickness. This is how rough-sawn lumber is sold at sawmills and hardwood dealers:
One board foot = a piece of wood 1 inch thick, 12 inches wide, and 12 inches long (= 1 ft³/12).
| Lumber Size | BF per Linear Foot | 100 LF = BF |
|---|---|---|
| 1×4 (actual 0.75" × 3.5") | 0.219 BF/LF | 21.9 BF |
| 1×6 (actual 0.75" × 5.5") | 0.344 BF/LF | 34.4 BF |
| 2×4 (actual 1.5" × 3.5") | 0.438 BF/LF | 43.8 BF |
| 2×6 (actual 1.5" × 5.5") | 0.688 BF/LF | 68.8 BF |
| 2×8 (actual 1.5" × 7.25") | 0.906 BF/LF | 90.6 BF |
| 2×10 (actual 1.5" × 9.25") | 1.156 BF/LF | 115.6 BF |
| 2×12 (actual 1.5" × 11.25") | 1.406 BF/LF | 140.6 BF |
| 4×4 (actual 3.5" × 3.5") | 1.021 BF/LF | 102.1 BF |
How to Calculate Linear Feet by Project Type
🪵 Lumber
Measure each board's required length and sum them. Lumber comes in standard lengths (8, 10, 12, 14, 16 ft) — round each piece up to the nearest available length. Add 10% for cuts and waste. Order the combination of lengths that minimizes leftover.
🏠 Baseboards & Crown Molding
Measure each wall's length. Subtract door widths (typically 3 ft per door, or measure actual opening). Sum all walls. Add 15% for miter cuts, corner waste, and length matching. Example: 12×15 ft room = (12+15+12+15) − 3 ft door = 51 LF × 1.15 = 59 LF to order.
🏡 Fencing
Walk the perimeter and measure each side. Add all sides. Subtract gate openings. Add 5–10% for posts and corner adjustments. Example: 50+40+50+40 ft yard = 180 LF − 10 ft gates = 170 LF + 10% = 187 LF.
🛖 Hardwood Flooring
Calculate room square footage. Divide by plank width (in feet) to get linear footage. Add 10–15% waste. Most flooring is sold by the box — confirm coverage per box with your retailer.
🌧️ Gutters
Measure the eave length along each side of the roof that needs a gutter. Sum all sections. Each downspout needs 10 LF extra (approximate for vertical drop). Add 5% for overlap at seams.
🪟 Window/Door Casing
Each standard door opening uses about 17 LF of casing (2 sides + top). A standard window uses 10–14 LF. Count your openings and multiply accordingly, then add 15% for miter waste.
Linear Feet Conversion Quick Reference Chart
| Linear Feet | Inches | Meters | Yards | Centimeters |
|---|---|---|---|---|
| 1 LF | 12" | 0.305 m | 0.333 yd | 30.5 cm |
| 5 LF | 60" | 1.524 m | 1.667 yd | 152.4 cm |
| 10 LF | 120" | 3.048 m | 3.333 yd | 304.8 cm |
| 25 LF | 300" | 7.620 m | 8.333 yd | 762.0 cm |
| 50 LF | 600" | 15.24 m | 16.67 yd | 1524 cm |
| 100 LF | 1,200" | 30.48 m | 33.33 yd | 3048 cm |
| 200 LF | 2,400" | 60.96 m | 66.67 yd | 6096 cm |
| 500 LF | 6,000" | 152.4 m | 166.7 yd | 15,240 cm |