Overview
This gutter calculator helps you plan roof drainage materials before purchase or installation. It estimates total gutter length, the number of hangers, and the number of downspouts based on your roof dimensions and spacing rules. Add a waste margin to account for cuts, joins, and on-site adjustments.
Use cases
- Estimating materials for a new gutter installation.
- Checking how many hangers are needed for a roof repair.
- Planning downspout placement for residential or commercial roofs.
- Ordering gutter parts with a proper waste allowance.
How it works
- 1
Enter the eave length in meters.
- 2
Provide the number of roof edges to be fitted with gutters.
- 3
Set the downspout spacing in meters.
- 4
Enter hanger spacing in centimeters.
- 5
Add a waste percentage for extra material.
- 6
Review the estimated gutter meters, hangers, and downspouts.
Examples
Example calculation
Input: Eave length: 12 m, roof edges: 2, downspout spacing: 10 m, hanger spacing: 60 cm, waste: 10%
Output: Estimated gutter length, hangers, and downspouts for the roof.
Use the result as a fast material estimate before buying components.
Planning a roof drainage upgrade
Input: Measure each eave section separately and sum the total length before calculating.
Output: A clearer estimate for gutters and supports.
Useful when replacing old gutters or expanding an existing system.
FAQ
How do I calculate gutter length?
Multiply the eave length by the number of roof edges, then add the chosen waste percentage.
How are hangers estimated?
Divide the total gutter length by the hanger spacing and round up to the next whole hanger.
How are downspouts estimated?
Divide the total gutter length by the downspout spacing and round up to get the required number of downspouts.
Why add waste percentage?
Waste covers cuts, overlaps, corner fitting, and installation adjustments.