Overview
The angle is easy. The reference is where the mistakes live.
Most miter calculators give you a number and send you back into the shop to guess what it means. This one stays honest about what you are measuring - outside, inside, or centerline.
It covers two workflows: frame corners and intersections. The output is simple: your saw setting, and a length that matches the reference you actually used to measure.
Best for
Frames, perimeter rails, braces, and repeatable miters that fit on the first try.
What it prevents
The classic "it is right but it does not fit" problem caused by reference drift.
If two people measure the same corner two different ways, the part is already wrong.