? If you want to learn more about wood beams and how to choose the correct wood species, grade, and size so you can avoid the need for knee bracings, you can check out our wood beam span calculator.

We can calculate the values of small right triangle sides, CAC_ACA​ and CBC_BCB​, using the trigonometric function tangent and the thickness of the plank, as shown below:

Knowing how to calculate angle cuts and using basic algebra and trigonometry are great things to learn, even if you already know how to measure angle cuts in wood using a protractor.

? Wait! If you plan to butt your knee bracings' ends on the surface of the post and beam, you can go ahead and cut those ends. However, if you plan to use mortise and tenon for your joints, make sure only to mark off these ends and cut only portions of them to leave your desired mortise.

This angle cut calculator, or woodworking angle finder, will help you determine the dimensions of angled planks used as knee bracing for your framing projects. In this calculator, you will learn what knee bracing is in structures and how to cut wood at an angle for bracing purposes.

When installing knee bracings, you may encounter many different situations that will lead to different starting points for your calculations. But don't worry; we will only need a few basic trigonometry concepts that work regardless of your starting point.

This calculator will help you start cutting angles for tightly fitting knee bracings in no time. Although we focus on knee bracing applications in woodwork, you can also use knee bracings in steel structures. Keep on reading to get started!

After finding the lengths AAA, BBB, and CCC, or just any two of these lengths, we can also determine the angle cuts α\alphaα and β\betaβ using the inverse of the sine, cosine, or the tangent formulas.

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From our example above, you can instantly determine the various dimensions and measurements of the knee bracing by entering the given values of plank thickness, length AAA, and length CCC in our angle cut calculator.

Let's say we need to install additional knee bracing supports 40 centimeters from the beam of an open shed framing, as shown below:

If you have a limited space to place your knee bracing, determine this space's measurements first and use it to calculate the length of bracing you will need. Using the hypotenuse formula, which is based on the Pythagorean theorem, we can find the outer length of our knee bracing as follows:

We also need to know the thickness of your plank or bracing material. This thickness should be consistent throughout the entire length of the plank. Once that is all set, we can now proceed to some of the different situations we can encounter.

Apart from knee bracings in wood and knee bracing in steel structures, you can also use our angle cut calculator for roof trusses and when installing supports for the formworks of retaining walls. You can learn more about roof trusses and retaining walls in our roof truss calculator and our retaining wall calculator

If you want to learn more about cutting boards and planks at an angle, perhaps you would like to check out our miter angle calculator. In our miter angle calculator (which is another woodworking angle finder), you will learn about what miter cut angle is, how it is different from miter saw angle, and so much more.

This formula can be used to solve the inner length of the knee bracing, too, if you know the inner measurements of the space you have. We can also utilize the Pythagorean theorem to solve for either length AAA or length BBB if we set a specific outer length for our knee bracing.

To properly use our calculator, make sure you enter the plank thickness (necessary) and any other two known measurements to find the unknown measurements. For best results, refresh the calculator when trying a new set of values.

If we need to use as much of 60-centimeter long and 10 cm wide planks as possible for our knee bracings, we can find the angle cuts by considering the right triangle formed by the open shade framing and our other known measurements, as shown below:

"Bevel" means in carpentry an edge cut at an angle other than 90 degrees, usually slopping. It tends to be more difficult and decorative than cutting at 45 degrees. The angle of a bevel cut ranges from a few degrees to 45 degrees and can be adjusted to achieve different shapes and angles.

In certain situations, we need to specify the correct angled cuts for the ends of our bracing material to fit perfectly. We can determine these angles using some basic woodworking tools. We can also use some trigonometry equations to calculate the cutting angles and any other related measurements.

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Due to the nature of the right triangles, we can easily calculate the value of angle β\text{angle}\ \betaangle β by finding the complementary angle of angle α\text{angle}\ \alphaangle α:

Angle cut refers to the angle needed to position a miter saw to cut wood into the desired number of sides. Cutting angles are most often used in the process of joining two or more pieces of wood, such as in carpentry.

If you do not have a protractor in your workshop, here is another method on how to cut wood at an angle. You can use the cutting angles α\alphaα and β\betaβ to determine other knee bracing measurements and mark them accordingly before cutting. By considering the illustration below showing the similar right triangles within the knee bracing, you can then mark where to cut on your plank:

In the image below, you'll see a post and beam structure with knee bracings installed for additional support, possibly because of beam deflection. You can read through our beam deflection calculator to expand your knowledge about it.

A knee bracing is a diagonal structural member that supports two members, like a column and a beam or a wall and a floor, usually at a perpendicular angle. The neatest way to install a knee bracing is by cutting the ends of the bracing material at certain angles so that one of its ends' surfaces meets the side of the vertical member and the other end meets the surface of the horizontal member.