Stitchbay guide
Increase evenly calculator: spread increases across a row
To increase evenly, divide the stitches into one more gap than the increases you need (one fewer than that in the round), and put an increase between each gap. The calculator does the sums and writes the row out, with the shorter gaps at the edges so the shaping sits inside the fabric.
Increase evenly
How it works
Say you have 64 stitches and need 72. That is 8 increases. Worked flat, 8 increases make 9 gaps, so the 64 stitches are shared between 9 gaps: 7 gaps of 7 and 2 of 8, or as close as the numbers allow. The calculator splits the end gaps in half so no increase lands on the edge stitch, where it would show in a seam.
In the round there is no edge, so 8 increases make 8 equal gaps: 8 stitches, then an increase, eight times.
Which increase to use
In knitting the calculator writes m1 (make one): lift the bar between the needles from front to back and knit it through the back loop. It adds a stitch without a hole. Kfb (knit front and back) is quicker to work but leaves a small bar; use it if the pattern asks.
In crochet an increase is two stitches worked into the same stitch, so it uses up one stitch of the row below: the calculator counts that.
Check your numbers
The row it gives is checked by the same stitch counter Stitchbay uses on its patterns before you see it: it always ends with exactly the stitches you asked for.
Questions
What does "increase evenly across the row" mean?
It means add the stitches spread out along the row rather than all in one place, so the fabric widens smoothly. The pattern leaves the spacing to you; this calculator works it out.
Can I increase more stitches than I have?
In knitting you can make up to two new stitches for each one you have in a single row, but it is better to spread a big increase over two rows. In crochet you can add at most one stitch for every stitch, by working two into each.
Does it work for decreasing too?
Yes: use the decrease evenly calculator, which writes k2tog (or sc2tog in crochet) between the gaps.