What bra size am I?

[Spartonian]

Please help, tried asking DH but he was useless.

I have measured when bent over and I'm 40.5" across breasts and 34" under breasts following the bra intervention guide.

34F?

Put your measurements into this calculator. When it says pull the tape tight it means tight

booborbust.com/

That came out as a 38B or 38C

M&S last measured me as a 36B and a 36D neither of those sizes fit.

I would say you’re right op, about a 34F. Also try a 32FF and a 34G.

If you were measured previously as a B then a D I can't imagine you're an F.

Go to Boux Avenue or somewhere and let them suggest bras for you to try when they measure because different styles come up at different sizes.

M and S are useless at fitting. You are no way a B with those measurements!

34E or F with those measurements - you shouldn't be adding inches

34E/F - you will need to try different style bra’s to get you best fit.

Booborbust wouldn't have given you 38B or C unless you input the info in the wrong boxes.

If you’ve measured first at 34 inches there’s no way you’ve put that correctly into BoB and got a 38B or C. Measure again, double check you’re really following the instructions and inputting into the right boxes.
M&S are always wrong and plus 4 on the band, never get fitted there

I re did the BoB and now have 32FF or 32G do not sure what I did wrong the first time.

That sounds more likely. Any chance you can get to a Bravissimo for a fitting? Or order a few different ones in both those sizes from Brastop to try? Like all clothes you’ll likely fit different brands and styles differently, breast shape will impact what sort of cup works best for you as well, so make sure you’re properly swooping and scooping all the breast tissue in and checking the fit, no folding at the bottom of the cups

I'm going to order t shirt bras to try as I find them most comfortable in a range of the suggested sizes.

Will look at brastop too

Thank you everyone my boobs will be happy

Worth bearing in mind that t-shirt style moulded cups are the hardest style to get fitting right, unless your boobs are perfectly pert and round.

Shape will make a huge difference to fit as well. If your breasts are fuller on the bottom then you need a differently cut bra to those full on the top, same goes for wide spaced or close set breasts so try lots of different styles as well.