What ratio should I use for dovetails?

Use 1:6 (about 9.5°) for softwoods like pine, which need a steeper angle to prevent the short grain from breaking. Use 1:8 (about 7.1°) for hardwoods like oak and walnut. 1:7 is a good general-purpose ratio that works well with most timbers.

How wide should dovetail tails be?

A common rule of thumb is that tails should be about twice the width of the pins, with half-pins at each edge about half the pin width. This gives an attractive, traditional look. Some woodworkers prefer equal pins and tails for a different aesthetic.

Half-pins are the small triangular pieces at the top and bottom edges of the pin board. They prevent the joint from sliding apart at the edges. Despite the name, they are typically about half the width of a full pin.

How deep should dovetails be cut?

The depth of the dovetail (also called the length of the tail) should equal the thickness of the mating board. If joining a 20mm thick board, the tails should be 20mm long. The baseline is scribed at exactly the board thickness.

Should I cut tails or pins first?

This is one of woodworking's great debates. The "tails first" method is traditional in the UK and allows you to use the tails as a template to mark the pins. "Pins first" is common in the US. Both methods produce excellent joints when done carefully.

WoodCalcs

Dovetail Calculator — Pin and Tail Spacing

Calculate dovetail pin and tail spacing for evenly distributed hand-cut or machine dovetail joints.

Board Width

Width of the board to be dovetailed

Board Thickness

Determines dovetail depth

Number of Tails

More tails = narrower spacing

Dovetail Ratio

1:8 for hardwood, 1:6 for softwood

How We Calculate This

This calculator spaces dovetail pins and tails evenly across the board width using traditional proportions.

Proportions used

Tail width = 2 × Pin width
Half-pin width = 0.5 × Pin width

The formula

Board width = 2 × half-pin + n × tail + (n−1) × pin

Substituting the proportions: Board width = 3n × pin width, therefore:

Pin width = Board width ÷ (3 × number of tails)

Dovetail angles

The dovetail angle = arctan(1/ratio). So 1:8 gives arctan(1/8) = 7.1°, and 1:6 gives arctan(1/6) = 9.5°.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify measurements and material quantities before cutting or purchasing.