Knitting Gauge Calculator
Cast on and rows from swatch gauge in inches or cm.
What it does
Gauge turns a swatch into a project. Stitches per inch times width gives cast on, rows per inch times length gives rows, and both come from one blocked square. This page runs both directions in inches or cm.
The default swatch is 20 stitches and 28 rows per 4 in for a 40 by 60 in piece. That gives 200 stitches to cast on and 420 rows to knit. Metric defaults use 20 and 28 per 10 cm for 102 by 152 cm and give 204 stitches with 426 rows, close but not equal since 10 cm is shorter than 4 in.
Swatch discipline decides fit. Knit larger than the measure window, wash and block as the finished piece will be treated, then count the middle where tension settles. Edge and cast on rows always read tight.
Use these counts as a base. Pattern multiples, selvages, borders, and shaping all round the raw numbers to working counts.
How to use
- Pick imperial or metric first.
- Enter stitch gauge from the swatch.
- Enter row gauge from the swatch.
- Enter finished width and length.
- Read cast on first, then rows and gauge.
Formula
- st gauge
- Swatch stitches per 4 in or per 10 cm.
- row gauge
- Swatch rows per 4 in or per 10 cm.
- width
- Finished width in the active units.
- length
- Finished length in the active units.
Gauge comes from a washed and blocked swatch measured over the middle 4 in or 10 cm. Edge stitches lie, so count inside them. Imperial and metric swatches differ by 0.16 cm per unit, which is why the two modes land 2% apart on the same nominal 20 count.
Worked example
Example: sweater blanket gauge
20 sts and 28 rows per 4 in, 40 in wide, 60 in long (metric 20/28 per 10 cm, 102 by 152 cm).
- Per inch: 20 / 4 = 5 sts per in.
- Cast on: 5 x 40 = 200 stitches.
- Per inch rows: 28 / 4 = 7 rows per in.
- Rows: 7 x 60 = 420 rows.
- Metric: 20 per 10 cm gives 204 sts and 426 rows.
- Tool shows 200 stitches and 420 rows imperial.
Reference table
| Width | Stitches | At 4 sts/in |
|---|---|---|
| 20 in | 100 | 80 |
| 30 in | 150 | 120 |
| 40 in | 200 | 160 |
| 50 in | 250 | 200 |
| 60 in | 300 | 240 |
Limits
- Stockinette base. Cables and rib need their own swatch.
- Ignores pattern multiples and selvages.
- One gauge per pass. Mixed stitch zones need splitting.
- Unblocked gauge will drift after wash.
Common mistakes
- Counting edge stitches in gauge.
- Measuring an unwashed swatch.
- Mixing 4 in with 10 cm counts.
- Rounding cast on before adding borders.
- Skipping a fresh swatch after needle change.
Try it yourself
Quick checks. Answers sit tucked under each question.
20 per 4 in, 30 in wide, 40 in long?
150 stitches (5 x 30), 280 rows (7 x 40).
16 per 4 in, 40 in wide?
160 stitches (4 x 40) at 16 per 4 in.
Questions
How many to cast on?
Stitches per inch times width. Here 5 times 40 is 200.
How many rows?
Rows per inch times length. Here 7 times 60 is 420.
How do I measure gauge?
Knit a 6 in square, wash it, then count 4 in across the middle.
What is that in metric?
204 stitches and 426 rows, since 10 cm is a touch less than 4 in.
Does gauge shift with stitch mix?
Yes, but rib and cables pull in. Measure blocked stockinette unless the pattern says else.
Does it size yarn?
No. Yardage, shaping, and edging sit outside stitch counts.