If you are certain that this will be your only upgrade, definitely go to a jewelry store and try on different carat weights. Once you do this, choose the largest stone (that looks the best on your hand) that you can comfortably afford. If you start out too small with your upgrade you will get diamond envy and eventually want larger. Trust me! On a 2.5 finger, I think 1 and 1/4 would look massive and lovely on you. Then once you halo it the finger coverage will be significant but not overwhelming. Plus it will have presence if you wear the ering alone. Good luck deciding!
Thank you! I’ve been messing about with diamdb.com & we like the coverage a 1.5ct solitaire would give me. Do you know what size centre stone I would need to get the same sort of coverage bearing in mind I’ll have a micro halo? I’ll be going into shops soon but enjoying the hunt & research online for now