Which size curtain rings for my pole?

[khuliloach]

The pole is up so I can't measure the diameter, but have measured around the pole and it's 9cm.

So what size rings do I need? Confused as in the shops and online all seem to be 28mm which seems very small though my pole is just a standard size.

Please help x

[AnythingNotEverything]

Isn't the diameter equal to the circumference divided by pi?

[khuliloach]

What is pi? How do I work this out?

[AnythingNotEverything]

Pi is 3.14. Circumference divided by 3.14 should give diameter ...

So 9/3.14 = 2.87cm, or 28.7mm

Does that look about right?

My maths is a bit sketchy ...

[khuliloach]

Your maths is brilliant! Thank you. Yes that does sound about right. So the standard 28mm would be too small.

Thanks again,