Miter angle calculator
Miter and bevel for frames, crown and boxes
The inside angle where the two pieces meet: 90 for a square corner.
Result
Miter
45.00°
Nearest ½°: 45.0°
Bevel
0.00°
Nearest ½°: 0.0°
- Corner angle
- 90.00°
- Turn at each piece
- 45.00°
- On a gauge that reads 90° when square
- 45.00°
Cut both pieces at this miter, one to the left and one to the right.
Miter angle calculator
Get the miter and bevel saw settings for picture frames and trim, crown molding on any wall corner, and boxes or planters with sloping sides — including corners that are not 90°.
Frequently asked questions
How do you cut a 45-degree angle?
The easiest way is with a miter saw: swing the table to its 45° stop, hold the piece firmly against the fence, and let the blade reach full speed before cutting. A hand saw in a miter box works the same way, using the box’s 45° slots.
With a circular saw, hold a speed square against the edge of the board: its long edge is at 45°, so you can mark the line and guide the saw’s base along it. Two 45° cuts make a 90° corner, as long as the corner really is 90°.
How do you cut perfect 45-degree miters for trim?
Start by measuring the corner, because walls are rarely exactly 90°. Take the angle with an angle finder or a sliding bevel, then cut half of it on each piece: a 92° corner needs two 46° cuts, not 45°. The calculator above splits any corner for you, including crown molding.
Check that your saw’s 45° setting is true by cutting two scraps and holding the joint against a square. Cut a little long and trim to fit, keep the trim tight against the fence, and mind the direction: on an inside corner the long point of each cut is at the back of the trim, and on an outside corner it is at the front.
Guides
About these measurements
Readings are estimates taken from rendered pixels and consumer device sensors. Do not rely on them for structural engineering, surveying, manufacturing inspection, navigation, or medical decisions. Check anything safety-critical with a calibrated instrument.
All processing happens in your browser. No image, camera frame or sensor reading is ever uploaded.
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