August 2026 update: This 2012 wizard is preserved as a historical tool. For the current calculator with updated width estimates and product options, use the Condom Monologues Condom Size Calculator.
Quick answer: how should you choose a condom size?
Nominal width is the width of a condom when laid flat—half its unstretched circumference. Use erect girth to estimate a starting width, then account for material, shape, and manufacturer instructions. A condom should stay in place without painful squeezing; if it repeatedly slips, breaks, or will not unroll comfortably, reassess the fit and technique.
Use the current Condom Size Calculator for updated product widths. For correct use, follow the CDC external-condom instructions.
NB: this tool is only a general guideline. In case a condom company provides specific instructions about the condom and erect penis size correspondence, please follow them.
Also try out this Condom Size Calculator to see what exact condoms you should buy.