Craft Sums
Free craft calculators with the maths shown: how much resin for a pour, quilt backing, batting and binding yardage, fabric yardage for pieces and curtains, cross-stitch fabric size, candle wax and fragrance per batch, yarn for any blanket, and knitting gauge adjustments.
Every craft has a "how much do I need" question, and every one of them is arithmetic on a measurement. These tools do the sum the way the guild, the supplier or the pattern designer would, show the rule they used, and give a table you can plan from next time.
Quilting and sewing covers backing, batting, binding and yardage. Yarn and stitching covers blankets, gauge and cross-stitch fabric. Resin and candles covers pours and batches.
Quilting & sewing
Backing yardage for any quilt top with the fewest seams, on 42-inch cotton or 108-inch wide backing, plus the batting size that fits and the binding strips and yardage.
Fabric yardageHow many yards of fabric for a number of cut pieces, with seam allowance and the best cutting orientation, and for curtains from rod width, length and fullness, on any fabric width.
Yarn & stitching
Finished design size and fabric to cut for any stitch count on 11, 14, 16, 18 and 22-count Aida or evenweave over two, with a framing margin, and a chart across every count.
Yarn for a blanketHow much yarn for a blanket of any size, in yards, metres and skeins, by yarn weight, knit or crochet, and stitch pattern, with a table for every standard blanket size.
Gauge adjustmentAdjust any knitting or crochet pattern to your swatch: new cast-on and row counts from the pattern gauge and yours, what size the pattern would come out unadjusted, and which way to change needle size.
Resin & candles
How much epoxy resin you need for a flood coat, a river table or a mold, from the dimensions and depth, in ounces, millilitres and grams, split into Part A and Part B for 1:1, 2:1 and 3:1 systems, with waste allowed.
Candle wax & fragranceWax and fragrance oil by weight for a batch of container candles or wax melts, from container size, count, wax type and fragrance load, with the maximum load for each wax.
Frequently Asked Questions
Where do the numbers come from?
The rules crafters already use by hand: resin volume is area times depth, quilt backing is the top plus four inches of overhang pieced across the fabric width, fabric yardage is pieces per width-of-fabric row, cross-stitch size is stitches divided by count, candle wax is container volume times a fill factor with fragrance as a share of wax weight, yarn is yards per square inch by weight, and gauge adjustment is a ratio. Each page states its rule and shows a table so you can check the result or work without the calculator.
Are these exact?
They are the standard estimates, and materials vary. Resins have their own mix ratios and depth limits, waxes their own fragrance ceilings, and no two crocheters use the same amount of yarn. Follow the label, swatch where a swatch is possible, and buy a little over. Running short of a dye lot or a resin kit mid-project is the expensive mistake.
Do I need an account, and is anything saved?
No account, nothing saved. Every calculation runs in your browser and nothing you type is sent anywhere.