Tapered Leg & Splay Angle Calculator

How it works

Taper angle = atan( (top − bottom) ÷ taper length ) per face (halve the difference when all four faces taper); splay spread = height × tan(splay); compound resultant = atan(√2 × tan splay)

A tapered leg is a wedge: the difference between the thickness at the top of the taper and at the foot, spread over the taper’s length, fixes a shallow angle — typically two to three degrees — that a taper jig reproduces by offsetting the foot end away from the saw fence. Two-face tapers on the inside faces are the classic Shaker and mid-century look; four-face tapers split the removal between opposite sides. Splayed legs add a second geometry: leaning each leg outward by a few degrees widens the stance for stability and style, and where legs splay in both directions at once the joint at the top becomes a compound angle, which is why many makers cut splay with a simple mitre in one plane and let the rail carry the other. Keep the taper clear of the joinery so mortises land in full-thickness stock.

Worked example

A 50 mm leg tapering to 28 mm over 620 mm on two faces: 22 mm removed per face at a 2.03° angle (1 in 28). An 8° splay on a 700 mm leg puts the foot 98 mm outside the joint line.

Frequently asked questions