Eave Length Calculator

Calculate total eave perimeter in linear feet for ordering starter strip, drip edge, gutter sections, and ice & water shield from building dimensions and roof configuration

Quick eave length from building footprint dimensions and roof type

Quick presets

ft
ft

Total Linear Feet

213 LF

Ridge: 50 LF • gable roof

PRO

Professional Calculator

Extended parameters for precise calculations

sq ft

Estimated Materials

60 bundles

Roof Area

1,792 sq ft

Squares

17.9

Detailed Breakdown

Roof Area1,792 sq ft
With Waste1,971 sq ft
Roofing Squares17.9
Bundles60
How to Use This Calculator
The Eave Length Calculator determines the total linear footage of eaves on your roof so you can order the correct quantities of starter strip, drip edge, gutter, and ice & water shield. These are linear materials that are surprisingly easy to underestimate, especially on complex rooflines with garages, dormers, and covered porches.

Simple Estimate tab: Enter your building length, width, roof type, and overhang depth. The calculator instantly computes the total eave perimeter. For a gable roof, eaves run along the two long sides only (the short ends are rakes). For a hip roof, eaves wrap around all four sides. The overhang adds length at each corner — a 12-inch overhang adds 2 feet to each eave run (1 foot on each end). This tab gives you a fast number for simple rectangular roofs.

Detailed Segments tab: Use this for complex rooflines. Enter each eave segment separately: main roof eaves, garage eaves, dormer eaves, porch eaves, and rake edges. This approach ensures nothing is missed. A common error is forgetting the garage eave when it has a separate roofline, or omitting dormer eaves that need their own starter strip and drip edge. The rake edge field lets you include gable-end edges for drip edge ordering even though they are not technically eaves.

Materials tab: Enter the total eave and rake linear feet and select your preferred products. The calculator converts linear feet into material quantities: starter strip rolls or bundles, drip edge pieces (10-foot standard), and gutter sections. It accounts for overlap at joints (2 inches for drip edge, per manufacturer spec) and applies your waste factor. The output tells you exactly how many of each item to order, preventing both shortages that delay the project and excess that wastes money.

The Formula
The eave length calculator uses these formulas:

Gable Roof Eave Length Eave LF = 2 × (Building Length + 2 × Overhang in feet) Example: 50 ft long, 12" overhang → 2 × (50 + 2) = 104 LF Rake LF = 4 × Rafter Length (2 gable ends × 2 rakes each)

Hip Roof Eave Length Eave LF = 2 × (Building Length + 2 × Overhang) + 2 × (Building Width + 2 × Overhang) Example: 50×30, 12" overhang → 2 × 52 + 2 × 32 = 168 LF Rake LF = 0 (hip roofs have no rakes)

Starter Strip Quantity Rolls = Total Eave LF × (1 + Waste%) / Coverage per Roll Example: 104 LF × 1.10 / 100 = 1.14 → order 2 rolls

Drip Edge Pieces Pieces = (Total Eave LF + Total Rake LF) × 1.10 (overlap) / Piece Length Example: (104 + 65) × 1.10 / 10 = 18.6 → order 19 pieces

Gutter Sections Sections = Eave LF × 1.05 (overlap + waste) / Section Length Downspouts = Eave LF / 35 (one per ~35 LF run) Example: 104 LF / 35 = 2.97 → order 3 downspouts
Example Calculation
Example: 50×30 Gable Roof with Attached Garage — Complete Eave Materials

Jennifer has a 50×30-foot gable-roofed home with a 24×24-foot attached garage (also gable), a small covered entry (8 feet wide), and 12-inch eave overhangs throughout. She needs to order all eave-line materials for a complete re-roof.

Step 1: Main House Eaves (gable — 2 long sides)
• Each eave = 50 + 2 × 1 ft overhang = 52 ft
• Main eaves: 2 × 52 = 104 LF

Step 2: Garage Eaves (gable — 2 long sides)
• Garage is 24 ft long parallel to its ridge
• Each eave = 24 + 2 = 26 ft
• Garage eaves: 2 × 26 = 52 LF (but one side ties into main roof, so effectively 26 LF additional)

Step 3: Covered Entry Eave
• Entry is 8 ft wide with 1 ft overhangs: 8 + 2 = 10 LF

Step 4: Rake Edges (for drip edge only)
• Main house: 30 ft wide at 5/12 pitch → rafter length ≈ 16.2 ft, 2 gable ends × 2 rakes = 64.8 LF
• Garage: 24 ft wide → rafter ≈ 13 ft, 2 gable ends × 2 rakes = 52 LF
• Total rakes: 116.8 LF

Step 5: Total Eave Length
• 104 + 26 + 10 = 140 LF of eaves

Step 6: Materials Order 1. Starter strip (roll, 100 LF/roll): 140 × 1.10 / 100 = 1.54 → Order 2 rolls (~$50) 2. Drip edge (10-ft pieces, eaves + rakes): (140 + 117) × 1.10 / 10 = 28.3 → Order 29 pieces (~$145) 3. Gutters (5" K-style): 140 LF → 140 LF gutter + 4 downspouts (~$1,000-$1,400 installed) 4. Ice & water shield at eaves (3-ft width, 36" up from eave): 140 LF / 65 LF per roll = 2.15 → Order 3 rolls (~$210)

Total eave-line materials: ~$1,405-$1,805

Frequently Asked Questions

What is an eave and how is it different from a rake?
An eave is the horizontal lower edge of a roof that extends past the exterior wall. It is where the gutter attaches and where water drips off the roof. A rake is the angled edge of the roof along a gable end — it follows the slope of the roof from the eave up to the ridge. The key difference matters for material ordering: eaves require starter strip shingles, drip edge, gutters, and ice & water shield. Rakes require drip edge and sometimes starter strip (manufacturer-dependent) but not gutters or ice shield. On a hip roof, all four edges are eaves because all four sides slope down to horizontal. On a gable roof, the two long sides are eaves and the two short angled sides are rakes.
How do I calculate eave length for a hip roof versus a gable roof?
For a gable roof, the eave length is 2 times the building length plus overhang adjustments. The short ends of a gable are rakes, not eaves. For example, a 50-foot building with 12-inch overhangs has eaves of 2 × (50 + 2) = 104 LF. For a hip roof, the eave runs around the entire perimeter because all four sides slope to the wall line. The same 50×30 building as a hip roof has eaves of 2 × (50 + 2) + 2 × (30 + 2) = 104 + 64 = 168 LF. The hip roof has 62% more eave length than the gable, which means more starter strip, drip edge, and gutter material. Always account for overhangs at corners — each corner adds twice the overhang to the total perimeter.
How much starter strip do I need per linear foot of eave?
Starter strip coverage depends on the product type. IKO Leading Edge Plus roll-type starter covers approximately 100 linear feet per roll and costs $20-$30 per roll. Starter shingle strips (pre-cut pieces) cover about 80 linear feet per bundle at $25-$40 per bundle. Field-cut starters made from inverted 3-tab shingles cover about 26 linear feet per bundle. For a 104 LF gable roof using roll starter: 104 × 1.10 (waste) / 100 = 1.14 rolls, order 2 rolls. Many manufacturers now recommend installing starter strip along rakes as well as eaves for wind uplift resistance, which would add the rake length to your order. Always check the specific product data sheet for exact coverage.
How many pieces of drip edge do I need?
Drip edge is sold in 10-foot pieces (some suppliers sell 12-foot pieces). You need drip edge along all eaves and all rakes. Calculate total linear feet of eaves plus rakes, add 10% for overlap at joints (each piece overlaps the next by 1-2 inches), and divide by 10. For a gable roof with 104 LF of eaves and 65 LF of rakes: total = 169 LF × 1.10 / 10 = 18.6 pieces, order 19 pieces. At $3-$8 per piece for standard aluminum drip edge, that is $57-$152 in drip edge material. Note that IRC code requires drip edge on all roof edges — eaves and rakes — for code compliance, and most shingle manufacturers require it to maintain the warranty.
Should I install gutters along every eave?
Gutters should be installed along every eave that drains water toward the foundation, walkways, or landscaping you want to protect. In most cases, this means all eaves. However, there are exceptions: eaves that overhang a gravel bed or rain garden with proper drainage may not need gutters; second-story eaves that drain onto a lower roof section do not need gutters at that level (the lower roof collects the water); and covered porch eaves that drain away from the house may be left without gutters in dry climates. For ordering, figure 1 downspout per 30-40 feet of gutter run, plus inside and outside corner pieces, end caps, and outlet fittings. A 104 LF gutter system with 3 downspouts typically costs $800-$1,500 installed for seamless aluminum.

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Hip Roof Calculator

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