Size Guide

Find your perfect fit — feel confident, comfortable, and supported.

Welcome to Moiraa’s comprehensive lingerie size guide. Whether you're shopping for bras, panties, shapewear, or lingerie sets, the right fit makes all the difference. This page will walk you through how to measure, how our sizes map to international standards, tips for a better fit, and answers to common sizing questions.

How to measure

Follow these steps with a soft measuring tape. Measure wearing a non-padded bra (or nothing) and stand relaxed.

1. Band / Underbust measurement

  • Wrap the tape measure snugly around your ribcage directly under your bust.

  • Breathe out normally and take the measurement in centimetres (cm) or inches (in).

  • This is your underbust measurement and determines your band size.

2. Bust / Overbust measurement

  • Wrap the tape measure around the fullest part of your bust (usually across the nipple line)

  • Keep the tape level and not too tight — comfortably snug.

  • This is your bust measurement.

3. Calculate your cup size

  • Subtract your underbust measurement from your bust measurement: Bust − Underbust = Cup difference.

  • Use the cup difference to find your cup letter (see the chart below).

4. Hip measurement (for panties & bottoms)

  • Measure around the fullest part of your hips and buttocks with feet together.

  • Keep the tape level and parallel to the floor.

Tip: If you're between two sizes, choose the larger band size for bras and consider the smaller size for panties if you prefer a snug fit. If undecided, reach out — we’ll help!

Bra size chart & cup calculations

For accuracy, all measurements below are shown in both centimetres (cm) and inches (in). Use the measurement you took.

Band size (Underbust)

Underbust (cm) Underbust (in) Typical Band Size
63–67 cm 24.8"–26.4" 30 (UK)/65 (EU)
68–72 cm 26.8"–28.3" 32 (UK)/70 (EU)
73–77 cm 28.7"–30.3" 34 (UK)/75 (EU)
78–82 cm 30.7"–32.3" 36 (UK)/80 (EU)
83–87 cm 32.7"–34.3" 38 (UK)/85 (EU)
88–92 cm 34.6"–36.2" 40 (UK)/90 (EU)

Note: Band sizing systems vary by brand and country. Use these as a guide and consult our international conversion chart below.

Cup size (difference method)

Cup difference (cm) Cup difference (in) Cup Size (A–G)
10–12 cm 4"–4.7" A
13–15 cm 5"–5.9" B
16–18 cm 6"–7.1" C
19–21 cm 7.5"–8.3" D
22–24 cm 8.7"–9.4" DD / E
25–27 cm 9.8"–10.6" DDD / F
28–30 cm 11"–11.8" G

Example: Underbust = 75 cm (→ 34 band), Bust = 91 cm → Difference = 16 cm → Cup = C → Result: 34C (UK).

Panty & bottom size chart

Panty sizes vary by cut (thong, brief, high-waist) and fabric stretch. Use hip measurement as primary guide.

Size Hip (cm) Hip (in) Equivalent
XS 82–88 cm 32.3"–34.6" 6–8 (UK)
S 89–95 cm 35"–37.4" 8–10 (UK)
M 96–102 cm 37.8"–40.2" 10–12 (UK)
L 103–110 cm 40.6"–43.3" 12–14 (UK)
XL 111–118 cm 43.7"–46.4" 14–16 (UK)

Tip: For thong-style panties, if you’re between sizes choose the smaller size for a sleeker fit. For full-coverage or high-waist pieces, size up for comfort.

International conversions

Here's a quick conversion table to help translate sizes between common systems.

Band size conversions (examples)

UK/US EU FR AU
30 65 80 6
32 70 85 8
34 75 90 10
36 80 95 12
38 85 100 14

Cup equivalence (general)

UK/US EU/FR
A A
B B
C C
D D
DD / E E / F
DDD / F F / G

Sizes and letter mapping can differ between brands — when in doubt, use measurements rather than labels.

Fit tips & troubleshooting

Band feels too tight

  • The band should be snug but breathable. If it digs into your skin or causes discomfort, try the next band size up and tighten the straps slightly.

Band rides up in back

  • This usually means the band is too loose. Go down a band size and increase cup size if necessary (e.g., from 36B → 34C).

Cups overflow / spillage

  • If your breast tissue spills over the top or sides of the cup, try a larger cup size.

Gaps in the cup

  • Gapping often means the cup is too large or the style isn't right for your shape. Try a different style (full cup, balconette, plunge) or go down a cup size.

Straps dig in

  • Straps take around 10–20% of support; if they dig in, check the band fit first. If the band is too loose, straps will carry more weight.

Center gore (bridge) doesn't lie flat

  • If the center doesn't sit against your sternum, you may need a different size or a different bra style.

Panty ride-up or shifting

  • Choose a size with adequate coverage and a fabric blend with higher elastane for better stay-in-place fit.

Fabric & style considerations

  • Stretch fabrics (microfiber, modal blends): allow more forgiveness — you might size down if you prefer a snug fit.

  • Non-stretch or structured items (lace with little elastane, corsetry, structured bralettes): choose your true measurements or size up for comfort.

  • Padding & push-up: adds visible volume; use measurements to choose a cup that accommodates the insert and your natural shape.

Care & maintenance for a perfect fit long-term

  • Hand wash or use gentle machine wash in a lingerie bag.

  • Use mild detergent — avoid bleach and fabric softeners.

  • Reshape cups and air-dry flat; avoid tumble drying.

  • Rotate bras — don’t wear the same bra every day to allow elastic to recover.


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