Miter Angle Calculator

Enter values in miter angle calculator to measure the correct angle for cutting materials when joining two pieces at a specific corner angle.

For example, when creating a picture frame with 90-degree corners, each piece needs to be cut at a 45-degree angle to fit together perfectly. The miter angle calculator helps determine these cutting angles for various corner configurations.

Miter Angle Calculator

Corner Angle	Calculation	Miter Angle	Conversion to Radians
60°	(180 – 60) / 2	60°	1.0472 rad
90°	(180 – 90) / 2	45°	0.7854 rad
120°	(180 – 120) / 2	30°	0.5236 rad
135°	(180 – 135) / 2	22.5°	0.3927 rad
150°	(180 – 150) / 2	15°	0.2618 rad

Conversion equation: Radians = Degrees × (π / 180)

Miter Angle Formula

The miter angle formula is:

Miter Angle = (180 – Corner Angle) / 2

This formula works for symmetrical joints where both pieces are cut at the same angle.

Let’s look at some examples:

For a 90-degree corner:
Miter Angle = (180 - 90) / 2 = 45 degrees

For a 120-degree corner:
Miter Angle = (180 - 120) / 2 = 30 degrees

Miter Angle Chart

Corner Angle	Miter Angle
60°	60°
90°	45°
120°	30°
135°	22.5°
150°	15°

How do you calculate miter angle?

To calculate a miter angle:

Identify the corner angle you’re working with.

Subtract this angle from 180 degrees.

Divide the result by 2.

For instance, if you’re working with a 108-degree corner:

Corner angle = 108°

180° – 108° = 72°

72° / 2 = 36°

The miter angle for each piece would be 36 degrees.

How to calculate miter and bevel angles

To calculate compound miter and bevel angles:

1. Determine the corner angle.
2. Use a compound miter angle calculator or specialized tables.
3. Find the corresponding miter and bevel angles for your specific corner angle and material slope.

For example, for a 90-degree corner with a 30-degree slope:

Miter angle ≈ 35.3°

Bevel angle ≈ 30°

Miter angles are cuts made across the face of the material, while bevel angles are cuts made through the thickness of the material. For compound cuts involving both miter and bevel angles, the calculations become more complex.

How to cut a 90 degree angle

Cutting a perfect 90-degree angle involves these steps:

1. Mark your cutting line precisely.
2. Set your saw to a 45-degree miter angle.
3. Make a practice cut on scrap material to ensure accuracy.
4. Cut your workpiece, ensuring the blade aligns perfectly with your mark.
5. Repeat for the adjoining piece.
6. Test fit the pieces to ensure they form a 90-degree angle when joined.

What is the formula for cutting angles?

The formula for cutting angles depends on the type of joint:

For miter joints: Cutting Angle = (180 – Corner Angle) / 2

For butt joints: Cutting Angle = (Corner Angle) / 2

What is the miter angle for 135 degrees?

Let’s calculate the miter angle for a 135-degree corner:

Miter Angle = (180 – Corner Angle) / 2
Miter Angle = (180 – 135) / 2
Miter Angle = 45 / 2
Miter Angle = 22.5 degrees

To create a 135-degree corner, you need to cut each piece at a 22.5-degree angle.

How do you miter a 140 degree angle?

To miter a 140-degree angle:

Use the miter angle formula: Miter Angle = (180 - 140) / 2 = 40 / 2 = 20 degrees

Set your miter saw to 20 degrees.

Cut both pieces at this angle.

When joined, these pieces will form a 140-degree corner.

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