Does the repeat have to divide the fabric width exactly?

Only for engineered or panel prints. For yardage, a partial repeat at the edge is normal.

Repeat Size Calculator

Calculate the repeat width that fits your fabric a set number of times, or how many repeats a chosen width gives — with the pixel size at your DPI.

How to use the Repeat Size Calculator

Choose whether you know the number of repeats or the repeat width.
Enter the printable fabric width.
Enter the repeat height and DPI for the pixel size.
Read the result and the fabric diagram.

The basic calculation

Repeat width = printable fabric width ÷ number of repeats. Printable width is usually the full width minus the selvedges. For example, 145 cm fabric with 1 cm selvedges leaves 143 cm; four repeats across gives a 35.75 cm repeat, which is 4,222 px wide at 300 DPI.