Using a Table Saw to Rip a board at an Angle

Minimum Guide Board Length

We can figure out how long our guide board needs to be by using trigonometry assuming we know the angle of the cut and the width of the board to taper. This will obviously need to be longer if we want to add guides.

If you know the angle and width of board, you can calculate the length at which the cut will exit the board.

Sin (angle) = opposite / hypotenuse

Opp = board width (BW)

Hyp = guide board length (GBL)

sin(6) = BW/GBL

GBL = BW/sin(ANGLE)

Given

Angle = 6°

BW = 4.25"

GBL = 5.25" / Sin(6) =  50.22"

References