Find out condom size?

The nominal width, i.e. the penis circumference, is not the length.

According to ISO 4074, the condom size is given in nominal width: and this is half of the size:

nominal width = circumference / 2

At 144mm penis circumference are the 72mm:

72 = 144 / 2

As an approximate guideline: the condom should have a somewhat smaller nominal width than half the penis circumference: A condom size of 60mm is for a penis circumference of somewhat more than 12cm.

The condom should have a slightly smaller nominal width than half the penis circumference in the fully erected state at the widest point.

It is thus ensured that the condom is not stretched strongly, but is nevertheless held by sufficient clamping force.

https://de.wikipedia.org/wiki/Condom

The condom should be tight, but not too tight and easy to roll.

If the condom is too large, friction is created. And friction increases the likelihood of a crack.

Different condom manufacturers have different recommendations (or size tables) that even change over time.

Many manufacturers offer size sets (1 pack with different sizes): ideal for testing.

MySize means you should try different sizes:

You can even playfully gain experience with different sizes: narrow condom – less sensations – delay your orgasm. Or: More condom – more intense sensation – faster coming!

https://www.my-size-condoms.com/dein-kondom/faq/