I believe that you are correct, but if your rc is 29, then you should be looking at a band size of 30 or 32.
From Zovo lingerie site:
Let's start with your band size...
With a bra on, measure where the band lies directly under your breasts and evenly around your back. Take the measuring tape and cinch it comfortably tight. We do not want a loose measurement here. Write this number down.
Actual band measurement Band size
Less than 27 inches 30 band
27  29 inches 32 band
29  32 inches 34 band
33  34 inches 36 band
35  39 inches 38 band
39  41 inches 40 band
42  43 inches 42 band
44  45 inches 44 band
Get your pen and paper out....
Subtract the actual band measurement (the first number you wrote down), from the second number. This is the only part that's a little tricky... Do NOT subtract your band size from the cup size. For example: if your band measurement is 30" and your cup measurement is 32", then the difference between these measurements is 2 inches, and you'd wear a Bcup.
1inch difference A Cup
2inch difference B Cup
3inch difference C Cup
4inch difference D Cup
5inch difference (DD) E Cup
6inch difference (DDD) F Cup
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