Angle Cut Calculator
Work out the miter angle and cut length for a piece that rises a certain amount over a certain run, handy for rafters, ramps, and trim.
What This Calculator Does
Enter the rise (vertical distance) and run (horizontal distance) of a slope or angled piece, and this tool calculates the exact angle you need to set your saw or miter box to, plus the length of the diagonal cut.
The Formula
The angle is found using basic trigonometry: angle = arctan(rise / run). The complementary angle (what many miter saws are marked in, measured from vertical) is simply 90 minus that angle. The cut length uses the Pythagorean theorem: length = square root of (rise squared + run squared).
This is useful for stair stringers, rafter birdsmouth cuts, ramps, and any trim carpentry where you need to translate a rise-over-run measurement into a saw angle. Always double-check with a physical square or protractor before cutting expensive material, since real-world framing can include additional offsets.