Condom Size Calculator: Girth to Nominal Width
Use your measured erect circumference to explore a starting point for condom nominal width. Nominal width is the width of the condom when laid flat, usually stated in millimetres on the packaging. Products and sizing guidance vary, so check the manufacturer’s information and instructions; this result is a guide, not a guarantee of fit or protection.
Why girth determines condom size, not length
Circumference is often the most useful starting point when comparing condom widths, but product design, length and material can also affect fit. Check the specific manufacturer’s guidance rather than assuming every standard or XL condom uses the same dimensions.
How to convert penis girth to nominal width
Measure circumference with a flexible tape around the erect mid-shaft without squeezing. Compare the result with the nominal width and sizing guidance on the product packaging. A simple mathematical conversion cannot account for every material, design or manufacturer, so use it as a starting point only.
Signs your condom does not fit properly
A condom should unroll as instructed, feel secure without painful tightness and stay in place during use. If it slips, bunches, feels restrictive or breaks, stop and follow the product instructions; consider a different size or product. Correct fit helps, but cannot guarantee that a condom will never fail.
My Size Report provides a private, calculator-led way to understand measurements against published research. Results are informational and should not be treated as medical advice.