BuildMaterialCalc

Roofing

Gutter & Downspout Calculator

Use this gutter calculator to estimate linear feet of gutter, downspouts, hangers, and elbows for any house or outbuilding. Built around standard residential 5" K-style gutter with 1 downspout per 30–40 ft of run.

Gutter Materials

Linear feet of gutter

120lin ft

For 120 ft of eave: 12 10-ft sections, 4 downspouts, 60 hangers. Estimated total: $1,251.

Linear feet of gutter
120 ft
10-ft gutter sections
12
Downspouts
4
Downspout footage
56 ft
Hangers
60
Elbows
8
Total estimate
$1,251

Formula

Gutter Length = Roof Eave Perimeter; 1 Downspout per 30–40 ft

How to use this calculator

  1. Measure eaves. Sum the linear feet of all roof eaves (the lower edges where gutters mount). Skip the gable ends.
  2. Enter story height. For downspout drop calculations. Typical 1-story: 10 ft; 2-story: 20 ft.
  3. Enter price per foot (optional). Aluminum K-style 5": $7–$12/ft installed. Seamless aluminum: $8–$14. Copper: $25–$40. Half-round: $12–$20.
  4. Read your bill of materials. Linear feet of gutter, sections (10-ft each), downspouts with footage, hangers, elbows, total estimate.

Formula

Gutter Length = Eave Perimeter; Downspouts = Length ÷ 35 ft

Worked example

A 2-story house with 120 ft of eave: 12 sections of 10-ft gutter, 4 downspouts (with 14 ft of downspout pipe each = 56 ft), 60 hangers, 8 elbows. At $7/ft + $6/downspout-ft + $1.25/hanger: $1,251 in materials.

Common project sizes

Quick reference for the most common gutter calculator use cases. Use these as a sanity check on your calculator inputs.

ProjectDimensionsResult
1-story ranch (1,500 ft²)120 ft eave12 sections · 4 downspouts · 60 hangers
2-story home (2,000 ft²)120 ft eave12 sections · 4 downspouts · 60 hangers
2-story with garage (2,500 ft²)180 ft eave18 sections · 6 downspouts · 90 hangers
Garage / shed (24 × 24 ft)48 ft eave5 sections · 2 downspouts · 24 hangers

2026 cost reference

Typical retail price range in the United States for gutter. Local pricing varies by region, supplier, and grade — confirm with two or three quotes before ordering.

Per linear foot (installed)

$7$40

Aluminum K-style 5" sectional: $7–$10/ft. Seamless aluminum: $8–$14/ft. Steel galvanized: $9–$13/ft. Copper: $25–$40/ft. Vinyl: $4–$8/ft (DIY-friendly but cracks in cold).

Tips for accurate results

  • 5" K-style is residential standard. Use 6" for high-rainfall zones, complex roofs, or roofs over 1,500 ft² of catchment per downspout.
  • Place downspouts every 30–40 ft of gutter run. Add an extra downspout at each corner where two gutter runs meet.
  • Slope gutters 1/4" per 10 ft toward the downspout. Most failures are flat or back-pitched gutters that pool water.
  • Hangers every 24" minimum, every 18" in heavy snow zones. Hidden hangers (clip inside gutter) are cleaner than spike-and-ferrule.
  • Always extend downspouts 4–6 ft from foundation with splash blocks or buried drain tiles. Foundations rot when downspouts dump at the wall.

When to consult a pro

Single-story gutter installation is workable DIY with a helper and an extension ladder. 2-story or higher: hire a pro — most gutter falls are from solo ladder work without a stabilizer. Seamless aluminum installation requires an on-site brake (machine that bends the gutter from coil), so DIY is limited to sectional aluminum or vinyl. Copper is always pro work.

FAQ

Frequently asked questions

  • A typical 2,000 ft² ranch has 120–180 ft of eave (depends on roof shape). A 2-story 2,000 ft² home with the same footprint has the same eave length. Plan 4–6 downspouts.

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