Miter marking tools

Tired of cutting miters on parts that need a precise length (like on a picture frame) with a slow trial-and-error? I designed these tools to accurately cut the length of mitered parts without iteration. Here's how to use them.

1) Cut a miter on either end of your part
2) Place the left or right miter tool on the part and align the angled miters until they are flush. Hold the miter tool in place with a spring clamp
3) Place the other miter tool on the end and measure between the "shoes" of the tool with a tape measure or ruler. The shoes accurately mark the outside dimension of the mitered piece - the total length from pointy tip to pointy tip.
4) Mark a line on the part along the angled miter edge of the positioned tool