What size is a fat quarter?

A fat quarter is approximately 50 x 56cm (18 x 22in). It is made by cutting a half-metre of 112cm-wide fabric in half along the fold, giving a squarer piece than a regular quarter metre.

What is the difference between a fat quarter and a long quarter?

A fat quarter is 50x56cm (wider, shorter). A long quarter is 25x112cm (narrow, full width). Fat quarters are better for cutting larger pieces; long quarters suit strips and borders.

How many 12.5cm squares can I cut from a fat quarter?

From a standard 50x56cm fat quarter, you can cut 4 across and 4 down = 16 squares at 12.5cm each. This is a common cut for 30cm (12in) finished blocks with seam allowance.

Should I pre-wash fat quarters?

For quilting, most quilters do not pre-wash. The slight shrinkage after washing gives a lovely crinkled look. If mixing with pre-washed fabrics or if the fabric bleeds colour, pre-wash and press before cutting.

SewCalcs

Fat Quarter Calculator — Pieces From Fat Quarters

Work out how many pieces you can cut from fat quarters.

Cut Type

Piece Width

Include seam allowance

Piece Height

Include seam allowance

Total Pieces Needed

How We Calculate This

The calculator determines how many pieces fit across the width and down the height of a fat quarter, then works out how many fat quarters you need.

The formula

Pieces across = floor(FQ width ÷ Piece width)

Pieces down = floor(FQ height ÷ Piece height)

Pieces per FQ = Across × Down

Fat quarters needed = ceil(Total pieces ÷ Pieces per FQ)

Frequently Asked Questions

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Last updated: February 2026

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