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Taper marking angle

o=W−wθ=arctan(oL)
where
o
offset (mm)
W
wide end (mm)
w
narrow end (mm)
θ
taper angle (°)
L
length (mm)
Explain this equation

Gives the edge slope for a taper with one straight edge and one sloping edge, as used on table legs or wedges.

L is the length of the taper, W the width at the wide end and w the width at the narrow end, all in millimetres. o is how much the sloping edge moves in. θ is the angle of that edge from straight, in degrees.

With one edge straight, all of the width change happens on the other edge, so o = W − w. The slope is o over L, and arctan turns that into an angle. For a symmetric taper the calculator halves the offset for each edge.

A 1000 mm piece going from 100 mm to 50 mm has a 50 mm offset and an angle of about 2.9°. Tapered both sides, each edge is about 1.4°.

Watch out: decide first whether the taper is on one edge or both.

Find the edge slope for a one-sided taper.

mm
mm
mm

Enter your values to see the result.

Good to know

One edge remains straight. For a symmetric two-sided taper, use half the width difference on each edge.

Sources

  • Geometry / arithmetic

This is a calculation aid, not a structural design or compliance certificate. Every default is an example, not a specification for your project.