Will scaling break my repeat?

Scaling the whole tile proportionally keeps it seamless as long as the result has whole-pixel dimensions. Re-check with the Seamless Pattern Checker after resampling.

Pattern Scale Calculator

How to use the Pattern Scale Calculator

Enter the current repeat width and the width you want.

Enter the file’s pixel size and DPI.

Read the scale factor.

Choose between resampling the file (option A) or keeping pixels and changing print size (option B).

Two ways to scale a repeat

Scale % = target size ÷ current size × 100. You can apply it in two ways:

Resample the artwork to new pixel dimensions at the same DPI (Photoshop: Image → Image Size with Resample on). Detail is preserved when reducing; enlarging invents pixels.
Keep the pixels and print larger or smaller. The effective DPI changes: enlarging by 200% halves it.

Example

A 30 cm repeat at 300 DPI (3,543 px) needs to be 20 cm for childrenswear. Scale is 66.67%: resample to 2,362 px at 300 DPI, or keep 3,543 px and print at an effective 450 DPI.