Condom Size Calculator
Fit is about girth, not length. Enter your erect girth and we'll size you up.
Condom Size Calculator
🔒 Everything is calculated on your device. Your numbers are never uploaded or stored.
Get condoms in your size
Standard boxes fit most men — but MyONE's 50+ custom widths let you dial in the exact fit instead of guessing.
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Why girth, not length, decides fit
Length mostly affects how far a condom unrolls, and standard condoms have plenty of slack there. Girth (circumference) decides how the latex grips. That's why the calculator only asks for girth.
What "nominal width" means
Condoms are sold by nominal width — the lay-flat width of the rolled condom. It runs a little narrower than half your circumference so the latex grips snugly. Standard condoms cluster around 52–54 mm, which fits the average erect girth of 11.66 cm (Veale 2015).
Snug, standard or large
Most men are standard. "Large" is a label, not an upgrade — and if you came out snug, that's the size that will actually stay on. Too tight risks breakage; too loose risks slipping. The full breakdown is in the condom-size guide.