Gutter calculator: linear feet, downspouts, and sections
Enter your home’s ground footprint and roof style to estimate total gutter run in linear feet, downspouts, hidden hangers, corners, end caps, and the number of 10-foot sections to order.
Calculator
- House perimeter160 ft
- Base gutter run (gable)100 ft
- Waste allowance (5%)+5 ft
- 10-ft sections to order11
- Downspouts (1 per 35 ft)3
- Hidden hangers (every 24″)53
- Corners / miters0
- End caps4
This calculator estimates total gutter run from your home’s footprint and roofline. Actual material depends on the eave layout, number of valleys feeding the gutter, and downspout drainage plan. Always confirm with your contractor’s measured take-off before ordering.
How to estimate a gutter job
Step 1: Measure the footprint. From the ground, measure the length and width of the house at the eaves. For a rectangular house this is straightforward; for an L-shape, break it into rectangles and add the runs that actually carry gutter.
Step 2: Identify the roof style. A gable roof has two sloped sides, so gutter runs along the two long eaves only. A hip roof slopes on all four sides and carries gutter on the full perimeter. Complex rooflines with dormers, bump-outs, and porch returns add length and corners.
Step 3: Add downspouts. Plan one downspout for every 30–40 linear feet of gutter, and at least one for every straight run. Each downspout needs an outlet cut into the gutter and a drainage path away from the foundation.
Step 4: Add waste and fittings. Straight runs waste ~5% on end cuts; a few corners push it to ~10%; complex runs with many miters and outlets waste ~15%. Budget hidden hangers every 24 inches, plus end caps, inside/outside corners, and outlet fittings.
Gutter sizing reference table
| Profile | Typical use | Downspout | Relative capacity |
|---|---|---|---|
| 5-inch K-style | Standard residential | 2x3 in | Baseline |
| 6-inch K-style | Large or steep roofs | 3x4 in | ≈ 40% more |
| 5-inch half-round | Historic / premium homes | 3-in round | ≈ 0.9x of 5-in K |
| 6-inch half-round | Large historic homes | 4-in round | ≈ 1.2x of 5-in K |
| 7-inch K-style | Commercial / very large | 4x5 in | ≈ 2x of 5-in K |
Source: SMACNA Architectural Sheet Metal Manual gutter sizing guidance. Final profile depends on roof drainage area, pitch, and local rainfall intensity.
Frequently asked questions
- How many linear feet of gutter does a house need?Gutter is measured in linear feet along the eaves that carry it. A gable roof carries gutter on the two long eaves; a hip roof carries gutter on all four sides. A typical 1,800–2,200 sqft single-story home runs 150–200 linear feet. The calculator estimates this from your footprint and roof style.
- How many downspouts do I need?The industry rule of thumb is one downspout for every 30–40 linear feet of gutter, with a minimum of one per straight run. Long runs, steep roofs, and high-rainfall regions push toward the lower end (one per 30 ft). The calculator uses one per 35 feet.
- What size gutter should I install — 5-inch or 6-inch?Five-inch K-style is the residential default. Step up to 6-inch K-style when the roof is large, steep, or sheds a lot of water into one run — 6-inch carries roughly 40% more water and pairs with 3x4-inch downspouts. The calculator estimates run length; your contractor sizes the profile from the drainage area.
- How is gutter sold and priced?Seamless aluminum gutter is formed on-site in one continuous run, so there are no 10-foot seams. Sectional gutter is sold in 10-foot sticks at home centers. Contractors quote installed gutter per linear foot, which includes hangers, end caps, corners, outlets, and downspouts.
Know your gutter run? Get real bids.
Two minutes of questions. A local gutter contractor reaches out through our lead partner with a bid based on your actual roofline. For what to verify before signing, see how we handle your quote request.
Start with my zip code