Choose a size with the surface in mind.
A sticker can look generous on a laptop and disappear on a shipping carton. Start with the actual surface: measure the clear space, including any edges, seams, hinges, or texture. Enter the finished width and height for a rectangle, or the finished diameter for a circle. The tool converts between inches and millimeters while keeping the same physical dimensions. Its measurement range is for planning; it is not a list of orderable sizes.
Compare proportions, then test on paper.
The reference card measures 3.5 × 2 inches. A 2 inch circle is the same height as that card, while a 3 × 1 inch rectangular sticker is shorter in both dimensions. Both shapes in the preview use one shared scale. The browser resizes the illustration to your screen, so placing a ruler against it will not give the finished size. Cut a paper mockup to your measurements and hold it against the intended surface instead.
Leave room for the words that matter.
Shape size alone cannot tell you whether a phone number, care instruction, or small logo will reproduce clearly. Keep essential content comfortably away from the cut and check text at its final physical size. These dimensions describe the finished shape, not a file with bleed. Confirm the production template, cut tolerance, material, and suitable surface before preparing final artwork. Download your specification to share the dimensions with a designer, then use the artwork checker to investigate image resolution. No artwork or measurements are uploaded by this calculator.