Increase & Decrease Calculator — Evenly Space Shaping

Use the "magic formula": divide your current stitch count by the number of increases PLUS ONE. The +1 centres the shaping so it is not jammed against the row ends. For example, 80 stitches and 10 increases is 80 / (10 + 1) = 80 / 11 = 7.27, so work an increase roughly every 7 stitches, spreading the 3 leftover stitches across the row. This calculator handles the maths including the leftover stitches.

Symmetrical placement centres the increases or decreases so that there are equal numbers of plain stitches at each end of the row. This gives a balanced appearance, especially important for garment fronts and visible edges.

Edge stitches (the first and last stitch of a row) form the selvedge which is used for seaming. Keeping these as plain knit stitches makes seaming easier and neater. Most patterns protect at least one stitch at each edge.

Yes. If you have rows available, the calculator will tell you how to spread the changes. For example, 10 increases over 20 rows means one increase every 2 rows. This creates smoother shaping than doing all changes in one row.

Not quite. A make-one (m1) increase adds a stitch without using up any of the existing stitches, so the plain runs between increases sum to your full current stitch count. A k2tog or ssk decrease, however, consumes TWO existing stitches to make one, so each decrease eats into the row. For the same 80 stitches with 10 decreases you divide the 60 stitches that remain after the decreases take their share (80 - 2 x 10 = 60) by 11, giving about 5 plain stitches between each decrease rather than 7. Working K5, k2tog ten times uses all 80 stitches and leaves 70 — the calculator handles this automatically.

When you remove more than about a third of the stitches, there is less than one plain stitch to sit between each decrease, so the calculator switches to a "k2tog across" instruction spaced every 2 stitches rather than quoting a nonsensical interval. Halving the stitch count (for example 80 down to 40) is exactly k2tog worked all the way across the row. A single row of k2tog can only ever remove half the stitches, so if your target is below half the calculator tells you to spread the remaining decreases over further rows. Edge stitch protection cannot add plain stitches that are not there, so on these heavy-shaping rows it simply steps aside — the stitch counts are always clamped so no segment is ever negative.