Gutter Calculator
Enter roof edge lengths for eaves and rakes separately to estimate seamless gutter footage and downspout drops.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
How to use this calculator
Eaves usually receive horizontal gutter; rakes may or may not depending on design.
What the math is doing
Total gutter LF = eaves length. Downspouts estimated as one per 35 LF of eave as a planning rule.
Frequently asked questions
Downspout size?
2×3 vs 3×4 changes capacity; counts here are generic.
Splash blocks?
Add accessories separately.
Leaf guards?
Linear feet matches gutter length.
Heat tape?
Measure affected gutter and downspout runs.