How do you measure for gutter guards?
Measuring width
On a ladder, measure straight across the top of the gutter from the inside edge of the front lip to the inside of the back wall at two or three points per run. Standard K-style gutters come out close to 5 or 6 inches; older or dented runs can vary. If one run measures differently from the rest, note it, because guards sized for one width will not seat right on the other.
Measuring length
Measure each run along the front lip, corner to corner or end to end, and write it down by side of the house. A measuring wheel along the ground directly under the gutter works for straight runs on level ground, but on sloped lots or where beds and decks interfere, measure at the gutter itself. Satellite measurement reports used for roofs can also list eave lengths, which approximate gutter footage.
Counting the extras
- Inside corners. Usually below valleys, where panels must be mitered.
- Outside corners. Where the gutter wraps around the house.
- End caps. Some guards need end pieces to close gaps.
- Downspout outlets. Note them; panels over outlets deserve the best fit.
Converting to panels
Guards are usually sold in fixed panel lengths. Divide total footage by the panel's effective length after the specified overlap, round up, and add about 10 percent for miter cuts and mistakes. Buy fasteners for the full count of panels. For sizing context, see gutter sizing and guards, and for how roofs are measured from imagery, how roofers measure a roof.