Swatch & StartYour workbench ↗

WASHED SWATCH / BEFORE & AFTER

Same swatch.
Two different dimensions.

See exactly how washing and blocking changed your swatch’s width, height and gauge. Keep the two directions separate.

How the calculation works ↓

Your measurements

Worked example is prefilled. Replace it with your measurements. Shared locally between these two pages.

Switching units converts lengths. 4 inches is 10.16 cm, not 10 cm.

01 / Counted area
Use the same counted area.
Use the same counted area.
02 / Before washing
A positive measurement.
A positive measurement.
03 / After washing & blocking
Measure after drying.
Measure after drying.
Optional / Pattern gauge

Enter the gauge exactly as printed. Leave one count blank if the pattern specifies only one axis. A gauge over 4 inches uses 4 inches, not 10 cm.

Leave blank to skip this axis.
A positive measurement.
Leave blank to skip this axis.
A positive measurement.
Optional / One section of your knitting

Estimate a simple span at these counts. Excludes edges, seams, shaping and ease.

Leave blank to skip this axis.
Leave blank to skip this axis.

THE MEASURED DIFFERENCE

Your swatch, before & after

Calculate to see your measurements.

A preview lets you confirm or cancel. Your project name, target size, repeat rule, yarn details and row history stay in place.

For a measured section in matching fabric. Not whole-garment grading or a fit guarantee.

Compare the same fabric, not two different areas.

  1. Mark an interior area. Count its stitches and rows. Keep away from borders and curled edges; use the same area for both measurements.
  2. Measure before finishing. Record width and height without pulling the fabric. Use centimetres or inches consistently.
  3. Wash, block and fully dry. Follow the yarn’s care instructions and your planned finishing method. Measure the marked area again in a relaxed state.
  4. Read width and height separately. The same piece can grow across and shrink vertically. Use the finished density for a simple section-size estimate.

Worked example: wider and shorter at the same time.

20 stitches and 28 rows occupy 10 × 10 cm before washing, then 11 × 9.5 cm afterwards. Width changes by +10%; height changes by −5%. Finished density is about 18.182 stitches and 29.474 rows per 10 cm. At that density, 100 stitches span 55 cm and 140 rows span 47.5 cm.

Change = (after measurement ÷ before measurement − 1) × 100%
Gauge = counted stitches or rows ÷ the matching measured span
Section size = section count ÷ finished gauge

One swatch becomes wider and shorterThe same 20 stitches and 28 rows measure 10 by 10 centimetres before washing and 11 by 9.5 centimetres after. Width grows 10 percent while height shrinks 5 percent.Before: 10 × 10 cmAfter: 11 × 9.5 cm
Original worked example · 20 stitches × 28 rows in the same marked area.

A 10% wider swatch does not mean every dimension grows 10%.

Applying one growth percentage to both directions would predict a 55 × 55 cm section in this example. The measured vertical result is 47.5 cm. Width and height are separate observations, and neither predicts another yarn or stitch texture.

Reversing the measurements is also not just reversing the sign: 10 cm → 11 cm is +10%, while 11 cm → 10 cm is about −9.091%. Each percentage uses its own starting measurement as the denominator.

What does “after blocking” tell me?

It records what happened to this swatch under this finishing method. It does not prove that a full garment will behave identically when worn or hung, or that a later wash will repeat the same change. Fibre, fabric, garment weight and treatment all matter. Avoid forcing a swatch to a target measurement and treating that as a relaxed gauge.

Use the pattern gauge diagnosis to compare the finished swatch against the pattern on both axes. When ready, send only the measured finished gauge to the cast-on calculator; it will still ask you to choose a legal stitch repeat.

Sources and boundaries

These are original calculators and worked examples. The Vogue Knitting substitution guide supports swatching a replacement yarn and checking gauge. Public discussions about a pattern gauge mismatch and size changes after blocking illustrate the questions this workflow addresses; community replies are not treated as calculation authority.

Nothing here estimates a universal blocking percentage, selects a sweater size or rewrites pattern instructions. Fractional measured counts are accepted; section stitch and row counts must be whole numbers. Results display up to three decimal places, while calculations keep the underlying precision.

Measurements are saved in a separate browser-local draft shared by these two pages. The existing project JSON format is unchanged and does not include this comparison draft. Record your before-wash measurements separately if you need a portable history. These pages do not load analytics or send measurements elsewhere. Existing public-entry analytics choices.

Use this finished swatch?