Dovetail Layout Calculator
Layout Dimensions
Marking Guide (Center-to-Center)
Mark centers of pins at these distances from the edge:
Understanding Hand-Cut Dovetails
The dovetail joint is the hallmark of fine craftsmanship. It relies on the mechanical strength of the "tails" locking into the "pins". While router jigs (like Leigh or Porter-Cable) constrain you to fixed spacing, hand-cutting allows you to vary the size and spacing for a refined, custom look—specifically, narrow pins that machines can't easily replicate.
Key Angles:
- 1:6 Ratio (~9.5°): Best for softwoods (Pine, Poplar) where you need a steeper angle to compress the fibers more for easier gluing and holding.
- 1:8 Ratio (~7.1°): The gold standard for hardwoods (Oak, Walnut, Cherry). It provides strength without leaving short grain at the corners that could chip off.
💡 Expert Tip
Mark with a Knife, Not a Pencil
A pencil line is roughly 0.5mm thick—that's huge in joinery terms! Use a marking knife to severe the wood fibers. This not only gives you a physical groove to register your chisel in but also prevents tear-out when you saw. "If you can't feel the line, you can't saw the line."
— Marcus Thorne, Master Cabinetmaker (30 years hand-tool experience)
⚠️ Common Mistakes
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Orienting Tails Wrong
Tails should almost ALWAYS be on the drawer sides, and pins on the front/back. This way, when you pull the drawer open, you are pulling against the mechanical interlock, not just the glue.
Exception: Sometimes reversed for decorative contrast. -
Pins Too Thin
While "london pattern" dovetails feature razor-thin pins for style, going too thin (under 1/8") makes it structurally weak and very hard to clear out the waste with a chisel without bruising the pin.
Correct: Keep pins at least 1/8" unless you have specialized saw files. -
Reviewing the Baseline
Sawing past the baseline is the most common visible error. It weakens the board.
Correct: Saw diagonally on the waste side, stopping just short of the line, and pare the rest with a chisel. -
Confusing Ratio with Degrees
Don't stress if your angle guide says 7° or 1:8. Functionally they are the same. Consistency across the joint matters more than the exact angle.
Frequently Asked Questions
What is a "half-pin" and why do I need it?
The half-pin is the outer socket at the very edges of the board. It needs to be substantial (usually wider than the internal pins) to support the joint edges and prevent splitting during assembly.
Can I use a router for variable spacing?
Yes, some advanced jigs (like the Leigh D4R) allow variable spacing, but standard fixed-finger jigs do not. This calculator is primarily designed for hand layout or custom variable jigs.
How deep should I cut?
The depth of cut is exactly the thickness of the mating board. If your drawer front is 3/4" thick, your tails on the side board must be cut 3/4" deep (plus maybe 1/32" to plane flush later).