Gutter & downspout calculator
Gutter, hangers, end caps, miters, outlets, downspouts, elbows, straps, sealant and guards.
Job
Gutters
Gutter
Size
Downspouts
Calculated — type to override
Materials list
| Item | Qty | Unit price | Cost |
|---|---|---|---|
| Gutters | |||
| 5 in. K-style seamless gutter2 runs | 102 LF | $ | — |
| End capshalf left, half right | 4 ea | $ | — |
| Outside miters | 2 ea | $ | — |
| Outlets / drops | 3 ea | $ | — |
| Hidden hangers (with screws)every 24 in. | 52 ea | $ | — |
| Downspouts | |||
| Downspout (2×3 in.)3 × 10 ft | 3 pcs (10 ft) | $ | — |
| Elbows (2×3 in.)3 per downspout | 9 ea | $ | — |
| Downspout straps / brackets | 9 ea | $ | — |
| Splash blocks / extensions | 3 ea | $ | — |
| Sealant & extras | |||
| Gutter sealant9 seams and joints | 2 tubes | $ | — |
| Zip screws (1/2 in.) | 1 bags (100) | $ | — |
How it works
- Downspouts default to one per 35 ft of gutter (at least one per run). Big or steep roofs may need more or 6 in. gutters.
- Each run has two end caps; corners use inside or outside miters. Sectional gutters add a splice every 10 ft.
- Add your supplier's unit prices to any line for a cost estimate; tax and markup are optional.
How to measure
- Measure along the fascia where gutters go. A “run” is a stretch with two open ends — wrapping a corner keeps it one run with a miter.
- Downspout length ≈ the eave height above the ground.
Estimates only. Coverage, sizes and waste vary by product and job — verify with the manufacturer's specs and your local building code before ordering.
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