Gosh interesting thread. I struggle with tight bra straps, but still don't get the adding/minusing 4 inches thing tbh.
I measure 32 under, 37 over, so should be a 32 D/E? I have tried 32 D/E bras before on this basis, but they were excruciating and there is no way I would have spent money on them. I have tried lots of styles and makes.
Out of interest, have just measured the strap length of three of my more comfortable bras:
Gossard 34D (full cup moulded)
Strap length unstretched: 28 inches
Strap length stretched (to the length I wear it at): 32 inches
The strap feels about right on this one, but the cup comes up a little too high at the front and under arms.
Gossard 36B (same style as above)
Strap length unstretched: 30 inches
Strap length stretched (to the length I wear it at): 32 inches
This one feels a little loose on the strap. The B cup fits better than the D cup on the 34D though.
M&S 36D (plunge style, moulded)
Strap length unstretched: 28 inches
Strap length stretched (to the length I wear it at): 32 inches
This one isn't really great for comfort tbh, the underwire scoops down at the bottom and digs into my rib cage. The strap feels ok though.
So from my (admittedly very unscientific and elderly bra sample) it seems like these strap sizes are already 'compensated' for in the adding 4 inches thing? ie:
- if you measure 32 under the bust, according to the eg M&S charts you are a 36
- the strap itself on a M&S 36 measures 28, but allows 4 inches for stretching to right size (32) when worn
Is this right? Or should they be stretching 8 inches? 