Quilting calculators that show their work
Every calculator here runs the same cutting engine, so the yardage it quotes is the yardage its cutting diagram actually uses. No rounded mystery numbers, no account, no email wall. Start with one calculator, or plan the whole quilt at once.
Backing yardage calculator
Panels, seams, and squaring allowance for any top size and fabric width, with the 108 in wide-backing comparison and a batting match.
Binding calculator
Strip counts and yardage for double fold, single fold, and bias binding, with fat quarter and jelly roll equivalents.
Border calculator
Cut lengths for up to three borders, butt or mitered corners, with the running quilt size after every border.
Sashing calculator
Strips, frame strips, and cornerstones for a block grid, plus the finished top size they produce.
Block yardage calculator
Fabric per role for a whole quilt of blocks: rectangles, half and quarter square triangles, flying geese, and strip sets, with the standard oversize-and-trim allowances built in.
Precut conversion calculator
Pieces to precuts, yardage to precuts, and honest one-for-one swaps between charm packs, layer cakes, jelly rolls, and fat quarters.
Project planner and shopping list
Blocks, sashing, borders, binding, and backing in one project. The planner re-packs every piece of each fabric together, so a fabric shared by the blocks and the border is bought once, at the true total. Print one shopping list with generic descriptions and no prices to argue with at the cutting counter.
One quilt, end to end
Say the quilt is twenty 12 in blocks in a 4 by 5 grid, with 2 in sashing and cornerstones. The sashing calculator gives a finished top of 54 x 68 in. Add one 4 in border and the border calculator moves the top to 62 x 76 in. The binding calculator then asks for 288 in of binding: 8 strips at 2.5 in from 44 in fabric, which is 5/8 yd to buy (or 3 fat quarters, and one jelly roll would bind five quilts this size). The backing calculator, with a 4 in overhang, works from a 70 x 84 in footprint: 2 panels cut 86 in each, 4 7/8 yd to buy, and a Twin packaged batting at 72 x 90 in covers it. Run the same quilt through the project planner and those numbers come back as one list, with the shared fabrics packed together.
How the numbers are made
Three rules sit under everything. Seam allowance is 1/4 in throughout. Usable width is the nominal fabric width minus 2 in for selvages and shrinkage, and it stays editable on every page if your fabric measures differently. Yardage is the exact bolt length the cutting plan needs, rounded up to the next 1/8 yd the way a shop cuts, with a 1/4 yd minimum. Each calculator page prints its formula in words and a worked example, so you can check the math with a pencil before you trust it with fabric.