What angle do I cut for a picture frame?

A four-sided frame uses 45-degree miters. Each of the four pieces is cut at 45 degrees so the two cuts at each corner add up to the 90-degree corner.

How do I calculate a miter angle for any number of sides?

Divide 180 by the number of sides. A hexagon (6 sides) is 30 degrees, an octagon (8 sides) is 22.5 degrees. Each piece gets that miter angle, set off the saw's zero (square) position.

What is a compound miter?

A compound miter combines a miter angle (the saw's left-right swing) with a bevel angle (the blade's tilt). You need both when the sides of a project lean outward, like a planter, hopper or crown-molding crown.

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Miter Angle Calculator

Get the exact saw settings for frames, boxes and any-sided project — pick the number of sides, dial in a custom corner, or add a side slope for compound miter and bevel cuts. Nothing is uploaded.

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Mode

Number of sides

3 = triangle, 4 = square/frame, 6 = hexagon, 8 = octagon…

Triangle Frame (4) Pentagon Hexagon Octagon

Saw settings

Miter angle

45°

miter angle (saw swing)

0°

bevel (blade tilt)

90°

corner / joint angle

pieces (sided frame)

45°

cut off square

Set your miter saw to this angle off its 0° (square) stop, and cut alternating ends. Test on scrap first.

Getting miter angles right

For a flat, even-sided project the miter on each piece is simply 180 ÷ number of sides: 45° for a four-sided frame, 30° for a hexagon, 22.5° for an octagon. Two of those cuts meet to form each corner. For an odd corner — say a 120° turn — each piece is cut at (180 − corner) ÷ 2. When the sides also lean outward (a planter, a hopper, crown molding) you need a compound cut: a miter angle for the saw's left-right swing and a bevel angle for the blade tilt. Most saws read the miter "off square," which is exactly the number shown here. Always test on scrap — a half-degree of error multiplies around every corner.

What angle for a picture frame?

45°. Four pieces each cut at 45° make the four 90° corners.

Miter for any number of sides?

Divide 180 by the number of sides — hexagon 30°, octagon 22.5°. That's the setting on each piece.

Cutting the parts to length?

Lay out and minimise offcuts with the cut list optimizer, then price the stock in the board foot calculator.