At TheyFit we use randomised codes (like M77, N17 or Z31) rather than explicit measurements to describe each of our 66 condom sizes.
We do this because many men find it tricky discussing their size requirements in explicit centimetre or inch terms - including when they interact with TheyFit customer services.
However, if you'd like to know what our size codes represent, you'll find the equivalent (mm) measurements here:
What is Nominal Width?
Nominal width is a condom industry term meaning "the diameter at or near the opening of the condom, when laid (squished) flat". Not many people have heard of it, despite it being printed on the box of every condom sold in Europe.
When choosing the best nominal width for your required condom size you need to factor in the correct amount of latex stretch to ensure both a comfortable & secure fit. Too small a nominal width and the condom will have to stretch too much to fit you - it will feel tight & uncomfortable and you won't feel much during sex. You may also lose your erection. On the other hand, too large a nominal width and the condom won't be stretching enough - it will be loose and during sex it may slip or fall off all together.
Divide your penile circumference by approximately 2.37, to find the optimum nominal width for your requirements. Alternatively, get fitted and we'll do the hard work for you.