Fat Quarter Count Calculator
Estimate how many fat quarters a quilt top needs from its finished size and a cutting-waste allowance.
How it works
Fabric = width × height × (1 + waste%) · Usable/FQ = 18 × 22 × usable% · Fat quarters = ⌈fabric ÷ usable per FQ⌉
A fat quarter is a quarter yard cut as an 18 × 22 in rectangle instead of a skinny 9 × 44 in strip, which makes it far more useful for cutting blocks. This estimate is area-based: it totals the quilt top, inflates it for seam allowances and trimming, then divides by how much of each fat quarter you can actually use. Real block layouts waste more or less depending on shape, so treat the count as a shopping floor, not a precise cut list.
Worked example
A 60×80 in top is 4,800 sq in. Adding 15% for waste gives 5,520 sq in. At 90% usable, one fat quarter yields 18 × 22 × 0.9 = 356 sq in, so you need ⌈5,520 ÷ 356⌉ = 16 fat quarters.
Frequently asked questions
How big is a fat quarter exactly?
A fat quarter is cut by halving a half-yard, giving roughly 18 × 22 in (sometimes 18 × 21 after squaring). That is the same area as a regular quarter yard but a friendlier, blockier shape.
Why can’t I use the whole fat quarter?
Seam allowances, squaring up the cut edges, fussy-cutting around motifs and leftover slivers all eat into the piece. Ninety percent usable is optimistic for simple patchwork and generous for complex blocks, so adjust the usable percentage to match your design.
Does this include the backing and binding?
No — it sizes only the quilt top. Backing usually needs continuous yardage rather than fat quarters, and binding is a separate cut. Use the quilt backing and quilt binding calculators for those.
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This calculator is for educational purposes. Double-check important results before acting on them.