How to Calculate Linear Feet: Complete Measurement Guide

Need fencing? Buying trim? Installing pipe? You'll hit "linear feet" on every quote.

Here's what most people miss: Linear feet measure length only—not width, not thickness, just straight-line distance.

Linear Feet = Total Length (in feet)

Simple? Yes. But mistakes still happen. Here's everything you need to know.

What Is a Linear Foot?

One linear foot equals 12 inches of straight-line length.

Examples:

• A 10-foot fence board = 10 linear feet
• Three 8-foot 2×4s = 24 linear feet total
• 150 inches of trim = 12.5 linear feet (150 ÷ 12)

Width and thickness don't matter for linear feet. Only length counts.

Think of it like measuring distance on a ruler—you're tracking how far something extends in one direction.

Linear Feet vs Square Feet vs Board Feet

This trips up everyone at first.

Linear Feet:

• Measures length (1 dimension)
• Used for: Trim, pipe, rope, fencing, lumber, molding, baseboards
• Formula: Length
• Example: 100 linear feet of baseboard

Square Feet:

• Measures area (2 dimensions)
• Used for: Flooring, paint, sod, roofing, carpet
• Formula: Length × Width
• Example: 400 square feet of flooring

Board Feet:

• Measures volume (3 dimensions)
• Used for: Hardwood lumber pricing
• Formula: (Thickness × Width × Length) ÷ 12
• Example: 25 board feet of walnut

Bottom line: Linear = how long. Square = how much surface. Board = how much wood volume.

How to Calculate Linear Feet

Step 1: Measure each piece in inches

Use a tape measure. Round to nearest quarter-inch for precision.

Step 2: Convert inches to feet

Divide by 12.

Example:

• Board 1: 96 inches ÷ 12 = 8 feet
• Board 2: 72 inches ÷ 12 = 6 feet

Step 3: Add all lengths together

8 + 6 = 14 linear feet

Quick conversion table:

| Inches | Feet | Decimal | |--------|------|---------| | 12 | 1 | 1.00 | | 24 | 2 | 2.00 | | 36 | 3 | 3.00 | | 48 | 4 | 4.00 | | 60 | 5 | 5.00 | | 72 | 6 | 6.00 | | 84 | 7 | 7.00 | | 96 | 8 | 8.00 | | 108 | 9 | 9.00 | | 120 | 10 | 10.00 | | 132 | 11 | 11.00 | | 144 | 12 | 12.00 |

Real-World Project Examples

Example 1: Fence Project

You're building a fence around your backyard:

• Front: 50 feet
• Left side: 75 feet
• Back: 50 feet
• Right side: 75 feet

Total linear feet = 50 + 75 + 50 + 75 = 250 linear feet

If fence boards cost $3.50 per linear foot: 250 × $3.50 = $875 for materials

Example 2: Baseboard Trim

You need trim for a room:

• Wall 1: 12 feet
• Wall 2: 15 feet
• Wall 3: 12 feet
• Wall 4: 15 feet
• Subtract 3 feet for doorways = -3 feet

Total = 12 + 15 + 12 + 15 - 3 = 51 linear feet

Baseboard costs $2.25 per linear foot: 51 × $2.25 = $114.75

Example 3: Crown Molding

Your living room measurements:

• 18 feet × 22 feet room
• Perimeter = 2(18) + 2(22) = 36 + 44 = 80 feet
• No door deductions needed (crown is at ceiling)

Order 80 linear feet of crown molding

Crown molding costs $4.50 per linear foot: 80 × $4.50 = $360

Example 4: Kitchen Cabinet Base Trim

L-shaped kitchen:

• Long wall: 16 feet
• Short wall: 10 feet
• Subtract for appliances and corners: -2 feet

Total: 16 + 10 - 2 = 24 linear feet

Example 5: Deck Railing

Deck perimeter: 12' × 14' = 48' total perimeter Subtract for stairs: -4' Subtract for house attachment: -12'

Railing needed: 48 - 4 - 12 = 32 linear feet

Converting Measurements

Inches to Linear Feet

Formula: Inches ÷ 12 = Feet

Example: 156 inches ÷ 12 = 13 feet

Yards to Linear Feet

Formula: Yards × 3 = Feet

Example: 20 yards × 3 = 60 feet

Meters to Linear Feet

Formula: Meters × 3.28084 = Feet

Example: 10 meters × 3.28084 = 32.8 feet

Centimeters to Linear Feet

Formula: Centimeters ÷ 30.48 = Feet

Example: 500 cm ÷ 30.48 = 16.4 feet

Miles to Linear Feet

Formula: Miles × 5,280 = Feet

Example: 0.5 miles × 5,280 = 2,640 feet

Pricing Strategies for Different Materials

Wood Trim and Molding

Baseboard (standard pine): $0.75 - $2.50/LF Baseboard (hardwood oak): $2.50 - $5.00/LF Crown molding (pine): $1.50 - $4.00/LF Crown molding (MDF): $1.00 - $2.50/LF Chair rail: $1.25 - $3.50/LF Casing (door/window): $1.00 - $3.00/LF

PVC and Composite Materials

PVC trim board: $1.50 - $4.00/LF PVC crown molding: $2.00 - $5.00/LF Composite decking: $3.00 - $8.00/LF Composite railing: $15 - $40/LF

Advantages: Rot-resistant, low maintenance, consistent dimensions Disadvantages: Higher upfront cost, can't stain (only paint)

Fencing Materials

Wood picket fence: $10 - $30/LF (installed) Chain link: $8 - $15/LF Vinyl fence: $20 - $40/LF Wrought iron: $25 - $35/LF Composite fence: $30 - $60/LF

Pipe and Plumbing

PVC pipe (1/2"): $0.35 - $0.60/LF Copper pipe (3/4"): $2.50 - $4.50/LF PEX pipe (1/2"): $0.40 - $0.80/LF Galvanized steel (1"): $3.00 - $6.00/LF

Corner and Miter Calculations

Inside Corners

Measure to the corner, not into it. Trim pieces will meet at corner.

90-degree inside corner: No length adjustment needed

Outside Corners

Measure past the corner to account for miter overlap.

90-degree outside corner: Add 1.5-2 inches per corner for miter cuts

Example: Wall with 2 outside corners: 12 feet wall length Add 3-4 inches total: 12.33 linear feet

45-Degree Miters

Crown molding and baseboards use 45-degree miters at corners.

Material lost to miters:

• 3.5" baseboard: ~2.5" lost per corner
• 4.5" crown: ~3" lost per corner
• 5.5" crown: ~3.5" lost per corner

Rule of thumb: Add 3-5% to account for miter cuts and fitting.

Bay Windows and Angles

Measure each angled section separately. Add all segments.

Bay window example:

• Center section: 5 feet
• Left angle: 2.5 feet
• Right angle: 2.5 feet
• Total: 10 linear feet

How to Measure Irregular Shapes and Angles

Curved Walls

Use flexible measuring tape or string method:

1. Run string along curve following wall
2. Measure string length
3. Convert to feet

Flexible trim: Add 5% for curve adjustment Rigid trim: Measure chord (straight line) instead, or use multiple short pieces

Staircase Trim

Baseboard on stairs:

1. Measure each riser height
2. Measure each tread depth
3. Use Pythagorean theorem: √(run² + rise²)

Example staircase:

• 13 risers × 7.5" = 97.5" total rise
• 13 treads × 10" = 130" total run
• √(97.5² + 130²) = 162.5" = 13.5 linear feet

Around Obstacles

Pipes, vents, radiators: Measure to obstacle, around it, then continuing.

Window/door casings: Measure all three sides (two vertical, one horizontal). Standard door: 7 feet + 7 feet + 3 feet = 17 linear feet casing

Professional Contractor Tips for Ordering

Order Extra for Defects

• Premium materials: +5%
• Standard materials: +10%
• Economy materials: +15%

Lower quality = more culled pieces with defects.

Account for Matching Patterns

Wood grain matching: +10-15% Decorative patterns: +15-20%

Cuts must align at corners for professional appearance.

Bundle Sizes and Waste

8-foot bundles: Efficient for 8' walls, generates waste on 10' or 12' walls 12-foot bundles: More versatile, less waste on varied wall lengths 16-foot bundles: Best for long runs, harder to transport

Strategy: Calculate total linear feet, then optimize bundle sizes to minimize waste.

Example: Need 85 linear feet total

• Option A: 11 × 8' boards = 88 LF (3 LF waste)
• Option B: 7 × 12' boards = 84 LF (need 1 more foot)
• Option C: 6 × 12' + 2 × 8' = 88 LF (3 LF waste)

Option A or C works. Choose based on price per piece.

Delivery Lengths

Available lengths: 8', 10', 12', 14', 16' (varies by material) Special order: 18', 20' (usually higher cost + lead time)

Long walls strategy: Use longest available lengths to minimize seams.

Material-Specific Waste Factors

Baseboard Trim

Waste factor: 10-15% Reasons: Corner miters, outlet cutouts, damage, bad cuts

Crown Molding

Waste factor: 15-20% Reasons: Complex compound miters, cathedral ceilings, pattern matching

Fencing

Waste factor: 5-10% Reasons: Straight runs, simple cuts, fewer mistakes

Piping

Waste factor: 10-15% Reasons: Fittings, angle cuts, test fits, errors

Chair Rail

Waste factor: 10-12% Reasons: Corner cuts, door/window returns

Deck Boards

Waste factor: 5-10% Reasons: Staggered seams, end cuts, board defects

Common Linear Feet Mistakes

1. Confusing with square feet

Linear = length only Square = length × width

Wrong: 12' × 15' room needs 180 linear feet of baseboard Right: Perimeter = 2(12) + 2(15) = 54 linear feet (minus doors)

2. Forgetting waste factor

Add 10-15% for cuts, defects, mistakes

Wrong: Need exactly 100 linear feet, order 100 LF Right: Need 100 LF, order 110-115 LF

3. Not subtracting openings

Doorways and windows reduce needed material

Wrong: 40-foot perimeter = 40 LF baseboard Right: 40 feet - 3 feet (door) - 6 feet (2 windows) = 31 LF

4. Mixing units

Convert everything to feet first

Wrong: 8 feet + 36 inches + 2 yards = 46 (incorrect units) Right: 8 feet + 3 feet + 6 feet = 17 feet

5. Rounding too early

Keep decimals until the final answer

Wrong: 12.7 feet → round to 13 → 13 × 3 = 39 Right: 12.7 × 3 = 38.1 → round to 39

6. Forgetting corner returns

Door casings and window casings have returns at floor/ceiling

7. Not accounting for seam locations

Seams should hit studs for secure nailing. May require different board lengths.

Adding Waste Factor

Always order extra for:

• Cutting mistakes
• Damaged pieces
• Matching patterns
• Future repairs
• Learning curve (DIY projects)

Standard waste factors:

• Straight runs: 5-10%
• Complex angles: 10-15%
• Pattern matching: 15-20%
• Beginner DIY: 20-25%

Example with waste:

You need 100 linear feet. Add 10%:

100 × 1.10 = 110 linear feet to order

Detailed Conversion Tables

Fractional Inches to Decimal Feet

| Inches | Decimal Feet | |--------|--------------| | 1" | 0.083 | | 2" | 0.167 | | 3" | 0.250 | | 4" | 0.333 | | 5" | 0.417 | | 6" | 0.500 | | 7" | 0.583 | | 8" | 0.667 | | 9" | 0.750 | | 10" | 0.833 | | 11" | 0.917 | | 12" | 1.000 |

Common Fractions

| Fraction | Decimal | Feet | |----------|---------|------| | 1/8" | 0.125 | 0.0104 | | 1/4" | 0.25 | 0.0208 | | 3/8" | 0.375 | 0.0313 | | 1/2" | 0.5 | 0.0417 | | 5/8" | 0.625 | 0.0521 | | 3/4" | 0.75 | 0.0625 | | 7/8" | 0.875 | 0.0729 |

Metric Conversions

| Metric | US Equivalent | |--------|---------------| | 1 mm | 0.0033 feet | | 10 mm (1 cm) | 0.0328 feet | | 100 mm | 0.328 feet | | 1 meter | 3.281 feet | | 10 meters | 32.81 feet | | 100 meters | 328.1 feet |

Cost Estimation Examples

Kitchen Backsplash Trim

Perimeter: 16 LF Material: Aluminum tile edge trim at $2.75/LF Cost: 16 × $2.75 = $44 With 10% waste: 17.6 LF × $2.75 = $48.40

Bedroom Baseboard

Perimeter: 48 LF Subtract for door: -3 LF = 45 LF Material: Oak baseboard at $3.50/LF Cost: 45 × $3.50 = $157.50 With 12% waste: 50.4 LF × $3.50 = $176.40

Deck Railing

Linear feet needed: 42 LF Material: Composite railing at $18/LF Cost: 42 × $18 = $756 With 8% waste: 45.36 LF × $18 = $816.48

Crown Molding for Great Room

Perimeter: 65 LF Material: MDF crown at $2.15/LF Cost: 65 × $2.15 = $139.75 With 18% waste (complex corners): 76.7 LF × $2.15 = $164.91

Frequently Asked Questions

What is a linear foot? One linear foot equals 12 inches of straight-line length. It measures distance in one dimension only—length. A 10-foot board equals 10 linear feet, regardless of width or thickness.

How do you calculate linear feet? Add up all lengths and convert to feet. If measuring in inches, divide by 12. Example: 48 inches + 72 inches = 120 inches ÷ 12 = 10 linear feet.

Is linear feet the same as feet? Yes, "linear feet" and "feet" mean the same thing. "Linear" emphasizes that you're measuring length only, not area (square feet) or volume (cubic feet). The term prevents confusion.

How many linear feet in a 12×12 room? Perimeter = 2(12) + 2(12) = 48 linear feet. This is how much baseboard trim you'd need (before subtracting doors). The room is 144 square feet of floor area.

Can you convert square feet to linear feet? Only if you know one dimension. Formula: Linear Feet = Square Feet ÷ Width. Example: 100 square feet of 10-foot-wide carpet = 100 ÷ 10 = 10 linear feet.

How much does linear foot measurement cost? Depends on material. Baseboard costs $1-5/LF. Crown molding costs $2-6/LF. Fencing costs $10-60/LF installed. PVC pipe costs $0.35-4.00/LF depending on diameter.

Do you need to add extra linear feet for waste? Yes, always add 10-20% depending on project complexity. Mitered corners, pattern matching, and defects require extra material. Professional contractors factor in 15% minimum.

How do you measure linear feet around corners? Measure each wall segment separately, then add them together. Don't try to measure through corners. For outside corners, add 1-2 inches per corner for miter overlap.

What's the difference between linear feet and running feet? No difference—they're identical terms. "Running feet" is less common but means exactly the same thing: length measurement in feet.

How do you calculate linear feet for fencing? Measure the total perimeter where fence will go. Don't include areas with existing structures (house walls, permanent obstacles). Add 5-10% for waste and post placement.

Pro Contractor Tips

Measure twice, order once: Confirm measurements before purchasing. Returns cost time and money.

Buy from same lot: Color and grain vary between manufacturing runs. Order all material at once for consistency.

Acclimate materials: Let wood trim adjust to room humidity for 48-72 hours before installation. Prevents warping after cutting.

Start with longest walls: Use full-length pieces on most visible walls. Save shorter pieces for closets and less visible areas.

Plan seam locations: Seams should hit studs for nailing. Locate studs before calculating cut lengths.

Use premium materials for visible areas: Save money using standard materials in closets, behind furniture, and other hidden locations.

Mark wall measurements on material: Label each piece with its location before cutting. Prevents confusion and mistakes.

Cut one, check fit, then cut rest: Never cut entire order at once. Verify first piece fits before proceeding.

Buy from supplier with good return policy: Extra pieces can often be returned within 30-90 days with receipt.

Calculate per-room, not whole-house: Easier to verify accuracy. Allows shopping for materials room by room as budget permits.

Ready to calculate your project? Use our Percentage Calculator for instant results, or explore our Unit Converter for all measurement needs.