Dovetail Calculator
Plan Angle =
Angles on Faces =
Timber Width =
Parallelogram on Deck
Supplement of Plan Angle =
Sides =
Plumb Dimensions on Faces
=
=
Projected Parallelogram
Angle =
Angle =
Sides =
Dihedral Angle between Projected Parallelogram and:
Deck (Level) =
End Face of Timber =
Side Face of Timber =
Saw Blade Bevel =

Diagram of Dovetail Dimensions and Angles

Dovetail Calculator Notes
Compound Angle : The Miter angles on the faces (Angles on Faces) of the dovetail and the Saw Blade Bevel angles created on each face are not necessarily equal as required by the Dovetail Calculator.
The Dihedral angles and Saw Blade Bevel angles created by unequal Angles on Faces can be solved using the Saw Blade Angle Calculator.

Section extracted from Dovetail showing the Compound Angle

Dovetail Calculator returns may be tested in the Non-Rectangular Cross-Section Calculator. For Plan Angle > 90° the value of μ required by this calculator is determined as follows. (NOTE: Values for Plan Angle < 90° have not been tested in this calculator)

90° - Angle on Face —> MIT
Projected Parallelogram Angle —> BEV
Dihedral Angle between Projected Parallelogram and Side Face of Timber
—> 180° - XDIH

LAG Program Entries :
(Set Select Entry Mode to Angular)
Main Pitch : 90° - 8.45862° = 81.54138° (MIT)
Adjacent Pitch : 64.20764° (BEV)
Total Deck Angle : 95.353548° (180° - XDIH)

LAG Program Returns :
Angle in Plan - 90° = 115° - 90° = 25°
P2m = 25.00000° —> α
Dihedral Angle between Projected Parallelogram and End Face of Timber
90° - P2a = 84.64645° —> YDIH
C5m = 70.61383°
C5a = 10.92755°
C5m + C5a = 70.61383° + 10.92755° = 81.54138° —> β
μ = arctan(tan YDIH sin β) arctan(tan 84.64645° sin 81.54138°) = 84.58792°

Non-Rectangular Cross-Section Calculator Entries :
(Refer to the diagram for definitions and locations of angles)
Miter Angle : μ = 84.58792°
Bevel Angle : β = 81.54138° —> 90° - Angle on Side Face
Cross-Section Angle : α = 25.00000° —> 90° - Plan Angle
Rectangle Width : 8
Rectangle Height : 8 (any value may be entered in this field)

Non-Rectangular Cross-Section Calculator Returns :
MIT = 81.54138° (90° - Angle on End Face)
BEV = 64.20764° (acute Projected Parallelogram Angle)
XDIH = 84.64645° (Dihedral Angle on End Face)
Blade Angle = 5.35355° (Blade Angle on End Face)
YDIH = 84.64645° (supplement of Dihedral Angle on Side Face)
Blade Angle = 5.35355° (Blade Angle on Side Face)
Cross-Section Triangle Dimensions:
Slope = 8.82702 (Parallelogram on Deck: Side)
Projected Triangle Dimensions:
length along slope of MIT = 8.92409 (Projected Parallelogram: Side)