Dovetail Layout: Angles, Spacing and Half-Pins Explained

Dovetails carry a certain weight of expectation, and the layout stage is where most of that anxiety lives. Look the subject up and you’ll run into numbers like 1:6 and 1:8 before anyone explains what they mean, alongside firm opinions about which is correct for what.

There’s more to decide than the angle, though. How many tails across the board? How wide should the pins be relative to them? What happens at the two ends? And do you need a special tool to mark any of it?

This guide covers layout — the decisions and marking-out that happen before a saw touches anything. Cutting dovetails by hand is a craft in itself and deserves its own article, which it will get. What follows should be enough to lay out a joint that looks deliberate rather than accidental.

What the ratio means

A dovetail ratio works exactly like a roof pitch: for every one unit across, the slope runs a set number of units along. A 1:6 ratio runs 6 along for every 1 across — a steeper angle. 1:8 runs 8 along for every 1 across — shallower.

In degrees, 1:6 is roughly 9.5°, and 1:8 roughly 7.1°.

Setting the angle without a dovetail marker

Dedicated dovetail markers exist and they’re pleasant to own, but you don’t need one — a ratio is just geometry, and you can lay it out with things you already have.

Take a square edge and mark six units along it (any unit — 6cm, 6 inches, six of anything). From that same starting point, mark one unit across, at ninety degrees. Join the two marks. That line is your 1:6 angle. Set a sliding bevel to it, lock it off, and you can mark every tail on the project from that setting.

Change the six to an eight and you have 1:8. The same trick works for any ratio you fancy trying, which makes it easy to experiment before committing to a tool.

The conventional guidance, and how strict it really is

The usual starting point: 1:6 for softwoods, 1:8 for hardwoods.

There’s real mechanical reasoning behind it. Softwood fibres compress relatively easily under load, so a steeper angle creates a stronger wedge-shaped lock that resists the joint pulling apart before the wood gives. Hardwood is denser and resists compression well on its own, so it doesn’t need as steep a lock — and a steep angle in hardwood leaves thin, fragile short grain at the tips of the tails, genuinely prone to snapping during cutting or assembly. The shallower hardwood angle isn’t just tradition; it dodges a real fragility problem.

That said, the rule is treated far more rigidly in writing than in practice. Look at antique furniture and you’ll find dovetails cut anywhere from about 7° to 14°. Plenty of experienced woodworkers say much the same thing: mechanically, anything in that range holds up fine, and with modern PVA glue doing structural work that a hide-glue era joint relied on the geometry alone for, the strict split is now as much about appearance and habit as necessity. A good number of woodworkers settle on a single compromise angle — 1:7 is a common choice — and use it for everything, so there’s only ever one bevel setting to find.

Where the range genuinely does matter:

• Steeper than about 1:4 (14°) — short-grain fragility at the tail tips becomes a real problem regardless of species.
• Shallower than about 1:9 or 1:10 — the joint starts to read visually as a plain box joint rather than a dovetail, losing the character that made you choose it.

Between those, the “correct” angle is more about how you want the joint to look than about whether it will hold.

Stock thickness plays a part too. A steep angle that reads as bold and confident in thick stock can look clumsy in something thin, and a shallow angle that looks refined in thin drawer sides can look timid in a thick case corner. Worth cutting a test joint in your actual material before committing to a full set of corners.

Half-pins: the bit that’s usually left out

Here’s something layout guides routinely skip, and it causes real confusion the first time.

Every dovetail layout begins and ends with a half-pin. Not a half tail — a half pin. The outermost element at each edge of the board is a pin that’s been, in effect, cut in half lengthwise, so it presents one angled face inward and one straight face flush with the edge of the board.

There’s a good structural reason. The pins are what resist the joint being pulled apart, and the edges of a board are where it’s most vulnerable to that force. A tail at the very edge would leave fragile short grain right where you least want it; a half-pin puts solid, straight-grained material there instead.

So a board’s layout reads: half-pin, tail, pin, tail, pin, tail, half-pin. Count the tails, and you’ll always have one more pin than tail once the two half-pins are counted as one whole between them.

Half-pins are usually made a little wider than the full pins, both for strength and because it simply looks better than a mean-looking sliver at the corner.

Spacing tails and pins

The angle gets all the attention, but spacing is what people actually notice when they look at a finished joint.

Two broad approaches:

Even spacing. All tails the same width, all pins the same width. Straightforward, machine-like, and completely legitimate — it’s what router jigs produce, and what a lot of good furniture uses.

Graduated or hand-cut spacing. Narrow pins with wider tails between them. This is the classic hand-cut look: fine pins, sometimes barely wider than the saw kerf at their narrowest, with generous tails. It signals hand work immediately, because no jig produces it, and many people find it the more attractive of the two.

There’s no rule for the ratio of tail width to pin width. Fine pins look elegant but leave less material to cut to and less glue surface; wide pins are more forgiving and more robust. Somewhere between “pins half the width of tails” and “pins as narrow as you dare” covers most of what you’ll see.

How many tails? Roughly speaking, more tails in wider boards and in finer work. A narrow drawer side might have two or three; a wide carcase side might have five or six. Spacing them out too far starts to look sparse, and packing them in too tight makes for a lot of very careful sawing.

Through and half-blind

Everything above applies to both.

A through dovetail shows on both faces — the standard for carcase corners and anywhere the joint is meant to be seen.

A half-blind dovetail is hidden from the front, with the tails stopping short of the outer face. It’s the traditional choice for drawer fronts, where you want the strength of a dovetail without seeing end grain on the front of the drawer.

The layout principles don’t change — only how deep the tails go and whether they emerge.

Tails first or pins first?

Both are used, both work, and woodworkers hold surprisingly firm views about it.

Tails first is the more common approach: cut the tails, then use them to mark directly onto the pin board. Pins first reverses that. The argument for each is essentially about which is easier to mark accurately from the other, and it varies with how you hold your work and how you see the lines.

If you’re starting out, tails first is the more commonly taught route, and there’s more material available describing it. But it’s genuinely worth trying both at some point rather than accepting the first one you learn as the only way.

Getting the numbers

Once you’ve settled on an angle, a tail count and how wide you want your pins, the dovetail calculator works out the actual tail and pin widths and the cutting angle for a given board, for through or half-blind joints — so trying a couple of layouts side by side costs a few minutes rather than a fresh sheet of arithmetic each time.

If you’re weighing dovetails against something quicker, the comparison with finger joints is worth a read — the strength difference between them is smaller than most people assume.

Lay one out on a scrap offcut before you commit to your good timber. Seeing the proportions full size tells you more in thirty seconds than any amount of deliberating on paper…