What is a bridle joint?

A bridle joint is essentially an open mortise and tenon. One piece has a slot cut into the end (like a fork), and the other has a tongue that fits into it. It is used for frame corners and T-joints where the end grain is visible.

How strong is a bridle joint?

Bridle joints are reasonably strong, offering good glue surface area and mechanical resistance to racking. They are not as strong as a mortise and tenon but are easier to cut and suitable for light frames, picture frames, and garden structures.

When should I use a bridle joint instead of a mortise and tenon?

Use a bridle joint when the end of the joint will be visible and you want a decorative look, when the frame members are the same size, or when you need a quick, reasonably strong frame joint. Mortise and tenon is stronger and better for furniture that takes heavy loads.

WoodCalcs

Bridle Joint Calculator — Frame Joint Dimensions

Calculate bridle joint dimensions for frame construction. Supports corner and T-bridle joints.

Stock Thickness

Stock Width

Joint Type

How We Calculate This

The bridle joint uses the same one-third rule as the mortise and tenon.

Dimensions

Slot width (tongue thickness): Stock thickness ÷ 3
Cheek thickness: (Stock thickness − slot width) ÷ 2
Slot depth / tongue length: Equal to the mating piece width

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.