My printed PDF is not actual size

If the 100 mm check ruler does not measure 100 mm, the PDF was scaled while printing. The file itself is exact.

Fix the print dialog

• Choose Actual size or Scale: 100 %.
• Turn off Fit to page, Fit to printable area and Shrink oversized pages.
• In browser print previews, set Scale to 100 and Margins to Default or None.
• Choose the paper the PDF was made for. Printing an A4 PDF on Letter (or the reverse) may trigger automatic scaling.

Still wrong?

• About 94–97 % — the printer driver is shrinking to fit its margins. Look for "borderless" or "printable area" options, or use the tiled PDF, which leaves room for margins.
• A design larger than the page — use the tiled PDF (cut-sheets-tiled-A4.pdf or Letter) and join the pages.
• Print from a desktop PDF reader rather than a phone or tablet app, which often scale silently.

Always measure the ruler before cutting a template.