Shaping
How to space increases evenly across a row
First decide whether you’re adding stitches across one row or gradually over several rows. Those are two different instructions.
Start with the change you need
Subtract your current stitch count from your target. Going from 100 stitches to 120 means you need 20 additional stitches.
For a single row, divide the existing stitches
With a make-one increase worked between stitches, divide your current 100 stitches by the 20 increases. That gives five existing stitches per increase.
One-row example: 100 → 120 stitches
Work [knit 5, make 1] 20 times. You work all 100 original stitches and add 20 new ones, finishing with 120 stitches.
This assumes your pattern permits a make-one increase at each of those positions, including after the last group. For flat knitting, edge stitches or a centered arrangement may require shifting the increase positions.
Your increase method matters
A make-one increase creates a stitch between existing stitches. A knit-front-and-back increase uses an existing stitch and turns it into two. With that method, [knit 4, kfb] 20 times uses the same 100 original stitches and ends with 120. Follow the increase method and placement your pattern specifies.
For multiple rows, plan the shaping rows
To add 20 stitches over 60 rows, one possible schedule is to add one stitch on rows 3, 6, 9, and so on through row 60. That is 20 increases in total.
If you need symmetrical shaping, adding two stitches on rows 6, 12, 18, and so on through row 60 also adds 20 stitches. The number of increases per shaping row changes the schedule. Right-side-only shaping and your pattern’s construction may impose other constraints.
Check the final count
For any schedule, multiply the number of shaping rows by the increases on each shaping row, then add that to your starting count. Follow your pattern’s placement instructions and count the stitches after shaping.
CozyKnit’s increase and decrease calculator (Pro) helps plan your stitch-count change. Keep “rows to spread over” at 1 for a single row, or change it when you want a schedule across several rows.