Measure diameter and pitch
For a round sticker, measure the cut circle's diameter. The round sticker calculator uses that diameter on both axes, then adds your horizontal and vertical gaps to create a rectangular grid. Its count is intentionally conservative: it does not try staggered or hexagonal packing.
If the stock is already die-cut, measure center-to-center pitch between neighboring circles. For equal diameters, the gap is pitch minus diameter. Measure the first circle's distance from the left and top paper edges as well as the available right and bottom space. Do not assume the circles are centered on the sheet.
Compare with a print
The preview shows circles, and PDF/SVG exports draw vector circle outlines. Print at Actual Size on plain paper, then compare the circles to the stock against a light source. The printer may shift or scale the output, so use the alignment test before consuming adhesive sheets.
If a package has an official manufacturer template, match its model code in the template finder. Use a custom grid only when you have the measurements needed to place every circle accurately.