What size condom do I need?
Most people fit a standard condom. Size is mostly about girth, not length: measure around the widest part of the shaft when erect. One major maker designs its regular condoms for a girth of about 4.25 to 5 inches. Go wider if a condom pinches or will not unroll to the base, and snugger if it slips.
Condom size is mostly about how wide a condom is, not how long. Cleveland Clinic's urologist puts it simply: most condoms fit most people, and for the vast majority standard sizes are the right choice (Cleveland Clinic, 2023). Length is rarely the problem. The FDA's minimum length for an external condom is 160 mm, about 6.3 inches, and any extra simply stays rolled at the base.
To measure, wrap a flexible tape around the widest part of the shaft when fully erect; that is your girth. Length runs from the base, where the penis meets the body, to the tip (Cleveland Clinic, 2023). Do it in private: the number is only for choosing a box.
Size names are not standardised between brands, so check the maker's own chart. As one example, Trojan's chart says most people wear regular condoms, which are made for a girth of about 4.25 to 5 inches. It suggests a large condom for a girth of at least 5 inches with a length over 7 inches, or when a standard condom feels too tight, and a snug condom below the regular range (Trojan size chart; cited as manufacturer information, not an endorsement).
Once it is on, the fit tells you what to change. Cleveland Clinic's chart lists slipping under both too big and too small, so change one thing at a time. Go up a size for a tight fit, no reservoir or a condom that stops short of the base. Try a smaller size for lots of rolled-up condom at the base or less sensation. For breaks, try a thicker material (Cleveland Clinic, 2023). Fit matters for protection as well as comfort: in a survey of 436 men, those who said their condom fitted badly were more likely to report breakage (adjusted odds ratio 2.6) and slippage (2.7) (Crosby and colleagues, Sexually Transmitted Infections, 2010).
Size only applies to external condoms. Internal condoms come in one standard size (Cleveland Clinic, 2023), and dental dams are flat sheets. For oral sex, the size you use for anything else works.
If you buy for more than one partner, or pack for a weekend away, keep a snug, a standard and a large option on hand rather than one box. The JoinTheSwing condom size guide has a full width chart, and the types-of-condoms guide covers materials and lube. This answer is general information from JoinTheSwing editorial, not medical advice.
How this answer was checked.
Written by JoinTheSwing editorial and not reviewed by a clinician; general information, not medical advice. Every figure was checked at the sources below on the review date. Manufacturer sizing is quoted as one brand's published chart, not a standard, and is not an endorsement.
- Cleveland Clinic, January 19, 2023
Condom Size Chart: Does Size Matter? (opens in a new tab)
Most condoms fit most people; measure a fully erect penis with a flexible tape, girth around the widest part of the shaft; too big can slip off and too small can break; the FDA minimum length for external condoms is 160 mm; Trojan's standard condom is listed for a 4 to 5 inch girth; FDA-cleared condoms for anal sex exist; the fit troubleshooting chart.
- Trojan (manufacturer)
Trojan and Magnum Condom Size Chart (opens in a new tab)
One manufacturer's sizing, cited as manufacturer information, not an endorsement: most people wear regular condoms, made for a 4.25 to 5 inch girth; a large condom may suit a girth of at least 5 inches with a length over 7 inches, or a standard condom that feels too tight; snug condoms are for sizes below the regular range.
- Crosby et al., Sexually Transmitted Infections, 2010
Does it fit okay? Problems with condom use as a function of self-reported poor fit (opens in a new tab)
Convenience sample of 436 men: the 44.7% who reported an ill-fitting condom were more likely to report breakage (adjusted odds ratio 2.6), slippage (2.7) and taking the condom off before sex ended (2.0).