About this calculator

Gutter length equals your eaves perimeter. Use one downpipe per ~50 m² of roof area and one bracket every 0.8 m.

Frequently asked questions

What does the Gutter & Downpipe Calculator do?

Estimate gutter run, downpipes and brackets needed for a house. Gutter length equals your eaves perimeter. Use one downpipe per ~50 m² of roof area and one bracket every 0.8 m.

Is the Gutter & Downpipe Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Gutter & Downpipe Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified roofing professional before committing to a purchase or a job.

What inputs does the Gutter & Downpipe Calculator need?

Enter values for: Total eaves length (m), Roof area drained (m²). Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Gutter & Downpipe Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.