How our calculations work

Know what goes into your estimate before you cut.

Backing

We add your chosen extra to all four sides. For each orientation, we find the number of full-width fabric panels needed, accounting for the fabric lost at every seam. Each seam consumes twice the seam allowance. We calculate the total length of those panels and round each purchase estimate up to the next eighth of a yard (or next 0.1 metre).

Both orientations are shown. The lower-yardage option may be unsuitable for directional prints or your quilter’s preferred seam direction. Diagonal piecing and print matching are not included.

Binding

Use the quilt binding calculator.

Required binding length is twice the sum of quilt width and length, plus the extra length you enter for corners and joining the ends. Every diagonal strip join consumes one strip-width of length. We choose enough full-width strips to cover that requirement, then multiply strip count by strip width to estimate yardage.

Borders

Use the quilt border calculator.

Enter the unfinished top dimensions measured through the centre. This tool plans one butt-joined border, with the two side pieces attached first. Cut strip width is the finished border width plus two seam allowances. Top and bottom pieces include the width added by both side borders. Long pieces are assembled using straight seams.

We allocate strips to each of the four border pieces separately. This conservative layout does not reuse offcuts between different borders. Mitered corners, diagonal joins, multiple borders and pattern matching are not included.

Units and rounding

One inch equals 2.54 centimetres and one yard equals 36 inches. Calculations use unrounded measurements internally. Purchase quantities round upward, never downward. Cutting dimensions are estimates: confirm them against your pattern.

About QuiltMetrix

QuiltMetrix is an independent fabric-planning project. Our focus is transparent calculations and readable cutting plans. It is not affiliated with a fabric manufacturer or quilting service. The calculators do not replace your pattern or your quilter’s instructions.

Backing purchase comparison

The backing cost calculator applies the backing panel calculation to two fabrics. Each can use either orientation or a fixed direction. We round the required length up to a multiple of that store’s purchase increment, then multiply by the entered unit price. Monetary totals round to two decimal places.

Changing shopping units converts prices, increments and available lengths to represent the same values. If another store sells in different increments, enter its increment. The approximate break-even price divides the other fabric’s purchase cost by this fabric’s rounded quantity; it assumes the other price and both quantities stay fixed.

The available-fabric check compares the unrounded cutting requirement with one continuous piece of usable fabric. It does not deduct stock from the purchase price, combine scraps, or include shrinkage, motif matching, shipping or tax.