How to Choose Condoms: Materials, Sizes and Getting the Fit Right
Latex, polyisoprene or polyurethane? Snug, standard or large? How to choose condoms that fit, feel good and work as intended.
Condoms are the only type of contraception that also helps protect against many sexually transmitted infections (STIs). But the material, size and fit all affect how comfortable they feel and how well they work. This guide covers how to choose the right ones and how to use them correctly.
How effective are condoms?
Used correctly every time, external condoms are about 98% effective at preventing pregnancy. In real life, when people sometimes make mistakes, they’re around 87% effective. That gap is why fit and correct use matter so much.
Condoms also lower the risk of STIs passed on through body fluids, such as HIV, chlamydia and gonorrhea. They offer less protection against infections spread through skin-to-skin contact, such as herpes and HPV, because they don’t cover all of the skin.
Condom materials
- Latex: the most common and affordable option, and very effective. Not suitable if you have a latex allergy, and not compatible with oil-based lube.
- Polyisoprene: a latex-free synthetic rubber that feels soft and stretchy. Suitable for most people with a latex allergy. Not compatible with oil-based lube.
- Polyurethane: a thin, latex-free plastic that transfers body heat well and works with any lube. It’s less stretchy than latex, so getting the right fit is especially important.
- Nitrile: a latex-free material mostly used for internal condoms.
- Lambskin (natural membrane): can help prevent pregnancy, but does not protect against STIs, because the material has tiny pores that viruses can pass through.
Finding the right size
Most condoms are long enough for most people. Width is what really affects fit.
Condom sizes are often described by their nominal width: the width of the condom when it’s laid flat. As a rough guide:
| Fit | Typical nominal width |
|---|---|
| Snug | Under about 52 mm |
| Standard | About 52 to 56 mm |
| Large | Over about 56 mm |
Sizing varies between brands. To choose, measure around the widest part of the erect penis with a soft tape measure, then compare it with the size chart from the brand you’re considering.
Signs a condom is too big: it slips, bunches up or comes off. Signs it’s too small: it feels very tight or uncomfortable, is hard to roll down, or breaks.
Thickness, texture and extras
- Thin and ultra-thin: offer more sensation. Quality-marked thin condoms go through the same safety testing as standard ones.
- Textured: ribbed or dotted condoms are about personal preference.
- Lubricated or non-lubricated: most are pre-lubricated. You can add extra water- or silicone-based lube.
- Spermicide-coated: nonoxynol-9 can irritate delicate tissue and doesn’t protect against STIs.
- Flavored: designed for oral sex.
Look for a quality mark on the package: FDA clearance in the US, or a UKCA or CE mark in the UK and Europe.
How to use a condom correctly
- Check the expiry date and make sure the wrapper isn’t damaged.
- Open it carefully with your fingers, not your teeth or scissors.
- Put it on before there’s any genital contact.
- Pinch the tip to squeeze out air, leaving space for semen.
- Roll it all the way down to the base. If it won’t unroll, it’s inside out: throw it away and start with a new one.
- Add water- or silicone-based lube to the outside if you need it.
- After ejaculation, hold the base of the condom while pulling out, before the erection goes down.
- Wrap it in tissue and throw it in the trash, not the toilet.
Use a new condom every time you have sex, and when switching between anal, vaginal and oral sex. Never use two condoms at once: the friction between them makes tearing more likely.
Internal condoms
Internal condoms (sometimes called female condoms) are worn inside the vagina or anus. They’re made of latex-free materials such as nitrile, can be put in ahead of time, and work with any type of lube. Used correctly, they’re about 95% effective at preventing pregnancy. Don’t use one at the same time as an external condom.
Storing condoms
Keep condoms somewhere cool and dry, away from heat and sharp objects. A wallet or a glove compartment is fine for a short time, but not for weeks, because heat and friction can damage them.
Frequently asked questions
What should I do if a condom breaks or comes off?
Act quickly. Emergency contraception works best the sooner it’s taken, and some types must be used within a few days. If there’s a risk of HIV, medication called PEP needs to be started within 72 hours. Speak to a pharmacist, doctor or sexual health clinic as soon as you can, and consider getting tested for STIs.
Do condoms expire?
Yes. Check the date on the wrapper and don’t use expired condoms, as the material can weaken over time.
Which lube works with which condom?
Water- and silicone-based lubes work with all condoms. Oil-based products weaken latex and polyisoprene condoms. See our guide to choosing lube or try the Lube Compatibility Checker.