What is bias binding?

Bias binding is a strip of fabric cut at 45 degrees to the grain. It stretches around curves smoothly, making it ideal for finishing necklines, armholes, quilt edges and curved seams. It can be single-fold or double-fold.

What width should I cut bias strips?

For single-fold binding, cut strips 4× the finished width. For double-fold binding, cut strips 6× the finished width. Common strip widths are 2.5cm (for 6mm finished), 4cm (for 1cm finished), and 5cm (for 12mm finished double-fold).

What is the continuous bias method?

Instead of cutting individual diagonal strips and joining them, you cut a square of fabric, mark lines, join two edges with an offset, then cut in a spiral to get one long continuous strip. It is faster and produces less waste.

How much extra should I make?

Always make 20–30cm more binding than you need. You lose a small amount at the start and end, plus you need overlap for joining. For quilt binding, add 25cm to the quilt perimeter.

SewCalcs

Bias Binding Calculator — Fabric for Continuous Bias Strips

Calculate the fabric square size needed to make continuous bias binding strips.

Binding Length Needed

Total length of bias binding required

Strip Width

Width of the cut bias strips

Price Per Metre (optional)

Fabric price per metre for cost estimate

How We Calculate This

The continuous bias method uses a square of fabric. The total area of the binding strips must equal the area of the fabric square.

The formula

Total strip area = Binding length × Strip width

Square side = √(Total strip area)

You need a fabric square with sides equal to the calculated length. The square is then marked, offset-joined, and cut spirally to produce one continuous bias strip.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before cutting or purchasing fabric.