Quick answer

Start with the cup size you wear in a Curvy Kate bra, then choose the bodysuit or teddy size that covers that cup and your hip measurement, not just your dress size. If the body has non-wired, non-padded cups, your usual cup size is the best starting point; if it is a stretch style with no cup structure, size to your largest measurement and expect a softer, less lifted shape. When in doubt, size up rather than down, because a bodysuit that pulls at the shoulder or digs at the gusset will not improve with wear.

Why your bra size is only half the answer

A bra is built around band tension and cup depth. A bodysuit or teddy has to do that job plus cover your torso, so the pattern is cut differently. That is why a 34G bra and a size 12 teddy can both be correct for the same person, and why a teddy size vs bra size chart never lines up one-to-one. The cup may be sized by letter, while the body is sized by a dress-equivalent number, and the two scales do not move at the same rate.

For a full bust, the risk is not the cup, it is the length. If the torso section is too short, the cups get pulled upward and the gusset rides. If it is too long, the bust sits low and the straps slacken. Use your bra size to judge cup capacity, then use your torso and hip measurements to judge the body.

Measure three things before you order

You need your underband, your fullest bust measurement, and your hip at the widest point. Compare those to the size chart for the specific style, because a structured teddy and a stretch lace teddy will not use the same grading. If the chart only lists dress sizes, check whether the brand publishes a cup range alongside it; if it does not, treat the fit as approximate and lean on the return policy.

  • Underband: keep the same number you wear in a bra, since this drives how the body anchors.
  • Fullest bust: use this to confirm cup capacity, not to pick the body size.
  • Hip: the most common reason a teddy feels tight even when the cups fit.
  • Torso length: compare the style's rise to a bodysuit you already own and like.

Match the style to the support you actually want

Structured cups behave more like a bra: they hold shape and give a defined neckline. Non-wired, non-padded cups sit closer to the body and rely on the fabric for support, so they suit a softer look and lower necklines. A stretch microfibre body with lace detailing will move with you but will not lift the way a wired bra does. Decide which of those you want before you look at sizes, because it changes which size is correct.

If you want a plunge or low neckline, look for ultra-low cups rather than sizing down to create cleavage. Sizing down shortens the torso and pulls the cups apart, which is the opposite of what a full bust needs.

Check the straps, gusset, and closure before you commit

Fully adjustable straps are the easiest fix for a body that is slightly long or short in the torso, so prioritise styles that offer them. A cotton gusset matters for all-day wear, and a snap or hook closure at the base makes bathroom breaks practical. If a style has none of these, it is a special-occasion piece rather than an everyday one, and you should size for comfort rather than for a second-skin fit.

Decision rules for sizing a bodysuit or teddy

  • Structured cups, wired or padded: Match the cup size you wear in a Curvy Kate bra and choose the body size that covers your hip measurement. Do not size down to gain cleavage; it shortens the torso and pulls the cups out of place. If the cup fits but the hip is tight, go up a body size and check whether the straps can be adjusted to compensate.
  • Non-wired, non-padded stretch cups: Your usual cup size is still the best starting point, but the body will follow your shape rather than reshape it. Prioritise the hip and torso measurements over the cup letter. Choose this construction when you want a soft, low-neckline look, not when you want lift.
  • Between two sizes: Take the larger size when the style has no adjustable straps or no stretch in the torso, and the smaller size only when the fabric is described as stretchy and the straps are fully adjustable. A bodysuit that is slightly loose can be adjusted; one that is too small cannot.
  • Plunge or ultra-low neckline: Look for the neckline in the product description rather than sizing down. Ultra-low cups give the plunge; a smaller size gives a shorter torso and a poorer fit. If no cup depth is listed, treat the fit as approximate and confirm the return window first.

How two real styles translate your bra size

  • Scantilly Embrace Stretch Lace Teddy Black: Scantilly Embrace Stretch Lace Teddy Black has ultra-low cups for a plunging neckline, butter-soft stretch microfibre with lace detailing, non-padded and non-wired cups, and fully adjustable 10mm straps. Because the cups are non-wired and non-padded, your usual cup size is a reliable starting point, and the adjustable straps let you correct a slightly long or short torso. Expect a softer, less lifted shape than a wired bra, and choose it for low necklines rather than maximum support.
  • Curvy Kate WonderFully Full Cup Side Support Bra Dark Blue: Curvy Kate WonderFully Full Cup Side Support Bra Dark Blue has stretch mesh top cup panels for a flexible fit, anchored back straps to reduce strap slippage, and a curved underband designed to reduce roll and discomfort. Use this as your reference bra when measuring for a bodysuit: the anchored straps and curved underband show the band tension a structured body needs to match. If your bodysuit cannot replicate that anchor, size up rather than expecting the same hold.
  • Curvy Kate Cool Cat Scooped Multiway Balcony Bra Coffee: Curvy Kate Cool Cat Scooped Multiway Balcony Bra Coffee has soft, stretchy mesh cups, scooped balcony cups for a lower neckline, and contains recycled fibres. The scooped balcony shape is the closest bra equivalent to a low-cut teddy, so if this bra fits you well, a teddy with a similar scooped or ultra-low cup is likely to suit your shape. The stretch mesh also means the cup tolerates small size variations better than a rigid cup.

Who this approach suits

Best for

  • Full-bust shoppers who already know their Curvy Kate bra size and want a bodysuit or teddy that fits the same way
  • Anyone choosing between a structured cup and a soft stretch cup for a low neckline
  • Shoppers buying online who want a repeatable way to pick a size without trying it on first

Not for

  • Shoppers looking for a bra-sized bodysuit with the same lift as a wired bra, since most bodysuits and teddies do not offer that level of support
  • Anyone who needs a style with no adjustable straps or no stretch, as there is little room to correct the fit