Ring Size

What ring size would fit a penny inside?
I don’t know what ring size my boyfriend wears, but one of his rings that fit can perfectly fit a penny inside. Odd question, i know, but I really need an answer. Thank you in advance!
you would be better off, measuring the diameter of the ring/penny. There are lists on the internet where you can find out the corresponding ring size.
Buying a Ring at the Right Size
Once you have found the diamond ring or gold ring you feel most appeals to you, you will need to make sure that you are buying the correct size. It is better to get the size right when you buy jewellery you want to offer to someone.
Different countries use different ring sizes but if you buy your diamond ring on a UK based website or at a jewellery shop in the United Kingdom, it will be UK ring sizing. Whereas UK ring size will usually be letters, European or American size will be numbers. It is good to know that UK Ring Sizes use British Standard (BS6820 or IS8653) which uses alphabetic letters for each 1.25mm of ring circumference with half sizes in between. Whether you buy online or in a shop, rings will be available from size J to size Q in whole sizes only. If you want to find out what your ring size is, or what your partner’s ring size is, we recommend two courses of action. The first one is with a ring sizer that show a circles of different sizes on a piece of paper. The second one is called a ring belt. You will easily find the ring size with either of those practical tools.
If your ring size is not between size J and size Q, a jewellery shop can often order the ring specially, sized especially for you, usually at a charged cost. This may take a little longer, around three to four weeks, as it will be made and delivered from their factory or another one of their shop. If however you need the ring urgently they will be able to have one of their standard rings re-sized for you. This would take approximately one to two weeks and there would be a re-sizing charge.
Tutorial: How to measure your ring size