How effective are condoms?
By spafe ·Reviewed 19 Jul 2026 ·Figures from healthdirect, Better Health Channel and Cochrane, each linked with a number where it appears and listed in full at the foot
Condoms are 98% effective at preventing pregnancy with perfect use, and about 88% effective with typical use1. That means 2 in 100 people relying on perfectly used condoms for a year will fall pregnant, and about 12 in 100 as condoms are actually used. Condoms are also the only method of contraception that protects against STIs, cutting HIV transmission by around 80% with consistent use4. And here’s the encouraging part. Those 10 lost points come down to late application, the wrong lube and the wrong size5, and you can fix all three yourself.
Condoms against every other method
Wondering how condoms stack up against the pill or an IUD? Here’s every method side by side, showing how each performs when it’s used perfectly and how it performs in real life, over a year of use1. Implants and IUDs barely change between the two readings, because once they’re in, your part is done. Condoms ask a little more of you in the moment, which is why their two numbers sit further apart, and why knowing your technique and your size pays off so well.
If you want the strongest cover of all, plenty of couples run a condom alongside an implant or IUD, pregnancy handled by one, STIs by the other. Clinicians suggest that pairing all the time.
What condoms protect against
Condoms are a physical barrier, so they’re strongest against infections carried in fluids, and weaker against infections spread by skin contact beyond what the condom covers. Here’s how that plays out, infection by infection.
Why typical use loses 10 points, and how to get them back
The condom in the packet is the same whether it’s used perfectly or badly. What changes the number is what happens in the moment. The research on condom errors keeps finding the same short list5, going in before the condom is on, no space pinched at the tip, oil-based lube on latex, and a condom that’s the wrong width, which is what drives most slipping and breaking.
Technique, sorted in one read
- On before any contact, off straight after.
- Pinch the tip as you roll it down.
- Water-based or silicone lube with latex, never oil.
- Hold the rim at the base to withdraw.
Fit, sorted with one measurement
- Slipping means the condom is too wide for you.
- Pinching or a ring at the base means too narrow.
- Both make failure more likely, not just discomfort.
- Nominal width is printed on every box. Buy by the number.
Things people ask
- Does “98% effective” mean 2% break? No. It means that over a year of perfect use, 2 in 100 people relying on condoms will fall pregnant. Per single use, the odds are far better than that number sounds.
- Are expensive condoms more effective? No. Every condom sold legally in Australia is TGA-listed and meets the same standard. Price buys thinness, texture or a material, not more protection.
- What actually happens if one breaks? There’s a clear plan, and the clock matters. Here’s what to do, hour by hour.
Sources
- healthdirect Australia, Contraception options (98%/88% external, 95%/79% internal, pill and LARC figures). healthdirect.gov.au/contraception-options
- healthdirect Australia, Condoms (STI protection by infection, correct use). healthdirect.gov.au/condoms
- Better Health Channel, Contraception choices (method effectiveness). betterhealth.vic.gov.au
- Weller S, Davis K. Condom effectiveness in reducing heterosexual HIV transmission, Cochrane Review (the ~80% figure). cochranelibrary.com
- Sanders et al., Condom use errors and problems: a global view, Sexual Health (2012). pubmed.ncbi.nlm.nih.gov
Common questions
How effective are condoms?
98% effective at preventing pregnancy with perfect use, and about 88% with typical use, per healthdirect Australia. The gap between those two numbers is technique and fit rather than the condom itself.
Do condoms prevent HIV?
They cut the risk substantially. A Cochrane review of couples where one partner was HIV positive found consistent condom use reduced transmission by around 80%. That is a large reduction rather than a guarantee, which is why PEP exists for when something goes wrong.
Can you still get an STI while using a condom?
For some infections, yes. A condom protects well against infections carried in fluids, such as chlamydia, gonorrhoea and HIV, and less well against ones passed by skin to skin contact outside the area it covers, such as herpes and HPV. healthdirect sets out which is which.
Can you get chlamydia if you use a condom?
It is far less likely, because chlamydia passes in genital fluids and that is exactly what a condom contains. Consistent and correct use is doing the work in that sentence, and it means every time, for the whole time.
Can you get pregnant using a condom?
On typical use, about 12 in 100 people relying on condoms for a year will. Almost all of that comes from the condom going on late, coming off, or being the wrong size, not from the condom failing on its own.
What causes most condom failures?
Putting it on late, using the wrong lubricant and using the wrong size, according to a study of condom use errors by Sanders and colleagues. All three are yours to fix, which is the encouraging part.
Move your number from 88 towards 98.
The condom already holds up its end. Fit and technique are yours, and both take minutes to get right.