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Bra Size Guide

28G Bra Size

Everything about the 28G bra size in United States sizing: what it means, its measurements, whether it runs big or small, sister sizes, and conversions to UK, EU, FR & AU.

Size profileModern snug method
Bra size · US
28G
Band 28 · Cup G · 7″ bust-band difference
Underbust≈ 27″ · 69 cm
Bust≈ 35″ · 89 cm
Difference7″ · G cup
UK28F
EU60G
FR75G
AU6F
IT0G
JP60G
Sister sizes · same cup volume
30DDDlooser band
Not sure 28G is your size? Calculate it →
Modern fitter method 8 sizing systems Sister sizes included
What 28G means

What is a 28G bra size?

Quick answer

A 28G in United States sizing is a bra with a 28 band and a G cup. “28” is the band in inches, taken from a snug underbust measurement rounded to the nearest even number. “G” is the cup, from a 7-inch difference between the bust and the band (one inch per cup letter). The same body is written as UK 28F, EU 60G, FR 75G, AU 6F, IT 0G.

Someone who measures roughly 27 inches (69 cm) around the ribcage and about 35 inches (89 cm) around the fullest part of the bust lands at 28G using the modern snug-measure method. The band carries most of the support; the cup describes the breast volume the bra needs to hold: measured relative to that band.

The band. 28

“28” is the band in inches, taken from a snug underbust measurement rounded to the nearest even number. It sets how the bra fits around the ribcage and provides about 80% of the support.

The cup. G

G is a fuller-bust cup: a 7-inch bust-minus-band difference. It reflects breast volume, always relative to the 28 band.

Read together

Band and cup are one size. A 28G is not the same volume as a 32G: the cup letter only has meaning next to its band.

Measurements

28G measurements

A 28G comes from two measurements: a snug underbust that gives the 28 band, and a looser bust. The cup is the gap between the two: for G, that gap is 7 inches.

7″ → G cup Band 28 Bust 35″ inches · underbust 27″ → US band 28
The cup letter is the distance from your band to your bust, not your raw underbust.
Measurements · 28Gcenter of range
MeasurementRangeSets
Underbust (snug)26.5–28.4″ · 67–72 cmBand 28
Bust (fullest)34.5–35.4″ · 88–90 cm—
Difference7″ · ≈ 18 cmCup G

Underbust rounds to the nearest even band; an odd reading (e.g. 27″) can go either way, so try 28G and 28G and let the band decide.

Measurements vary by body shape, so treat these as the center of a range.

Context

Is 28G big or small?

28G is a full-bust cup on a petite band: carried by full-bust specialists more than mainstream ranges. But the honest answer is that a cup letter is not a fixed amount of volume: it grows with the band. Tap a size below to see how.

28G
this size
30G
larger
32G
larger
34G
larger
36G
larger

All five are G cups, yet the volume grows with the band. 28G is the highlighted size.

Because the cup is measured relative to the band, a 28G holds more than a 28G and less than a 36G, even though all three are “G cups.” So “big” or “small” only has meaning once you know the band.

If 28G cups fit well but the band feels off, you don't need a different cup: you need a sister size. And if you're unsure 28G is your starting size, the calculator settles it from two measurements.

Method check

Were you measured as 28G correctly?

Most people wearing the wrong size were sized by the old “+4 rule”: adding four inches to the underbust to get the band. It inflates the band and, because the cup is the difference from that inflated band, understates the cup by about two letters.

If a +4 chart said28G Your snug underbust is likely≈ 23–24″ (58–61 cm) Snug-measure sizeoutside the standard range

Same body, same volume: the old rule pushes it into a looser band and a smaller cup.

The tell-tale signs you were sized with the old method: the 28 band rides up at the back, you fasten it on the tightest hook from day one, and the straps do most of the work. If that sounds familiar, measure again with a snug tape: it holds the same volume on a band that actually supports.

Key takeaway: if a calculator adds inches to your underbust, its 28G is not the same 28G as ours. Brasize.ai uses the modern snug-measure standard used by professional fitters.

Construction

Which bra styles fit a 28G best?

At this depth the bra is doing real load-bearing work. Prioritise full-cup and side-support constructions from full-bust specialists, firm (often three- or four-hook) bands, and wider straps. Molded single-piece cups rarely fit well here; seamed cups distribute weight and shape better. On a petite frame like a 28 band, also look for narrower wires and shorter straps: many mainstream ranges draft their wires for average frames, which is why small-band sizes can feel wide at the side even when the cup volume is right.

1Cup shape

Full-cup and side-support constructions from full-bust specialists.

2Band & hooks

Look for a three-hook band with firm, wide elastic: the band does the lifting.

3Wire & straps

Narrower wires and shorter straps suit a 28 frame.

Sister sizes share cup volume but not cup shape: the wire on a smaller band is narrower and more projected, the wire on a larger band is wider and shallower. If you have a narrow breast root, the snugger sister will often fit better; if your root is wide, the looser sister may: even when the band tension of the original was right.

Sister sizes

28G sister sizes

Sister sizes hold the same cup volume as 28G on a different band. They're the fix when the cups fit but the band is too loose or too tight.

Sister sizes · same cup volumeband ↔ cup
SizeBand feel vs 28GCup volumeWhen to try it
28GYour starting size—Band sits firm and level
30DDDOne band looserSame as 28G28 band digs in or feels tight
32DDTwo bands looserSame as 28GRarely right: the band gives up too much support

The rule: go down a band and up a cup for the same cups on a tighter band, or up a band and down a cup (28G → 30DDD) for the same cups on a looser band. Sister sizes share cup volume but not cup shape: the wire on a smaller band is narrower and more projected, the wire on a larger band is wider and shallower. If you have a narrow breast root, the snugger sister will often fit better; if your root is wide, the looser sister may: even when the band tension of the original was right.

Open 28G in the sister-size calculator →

Diagnose

Signs 28G is too small, or too big

28G is too small if…· Spillage over the top or sides of the G cups (“double-bust”)· The center gore lifts away from the sternum· Underwire sits on breast tissue rather than the ribcage· Cups feel full only after adjusting the breasts into them

Fix: go up a cup on the same band → 28H. If the band is also loose, go to the snugger sister.

28G is too big if…· The G cups wrinkle or gape at the top when you move· The band rides up at the back even on the tightest hook· Straps slip off or need constant tightening· You can lift the band more than two fingers away from your ribs

Fix: gaping cups → down a cup, 28DDD. Band riding up with cups that fit → the snugger sister.

International sizes

28G in UK, EU, FR & AU sizing

The same 28G body measurements are written differently around the world. Bands and cup letters diverge by region, so convert deliberately when buying from an international brand.

28G around the worldUS → world
RegionSizeHow the band is derived
United States (US)28GBand in inches
United Kingdom (UK)28FSame band as US; cups diverge above DD
Europe (EU)60GUS band × 2.5 − 10 = 60
France / Spain (FR)75GEU band + 15 = 75
Australia / NZ (AU)6FUS band − 22 = 6
Italy (IT)0G(EU − 60) ÷ 5 = 0
Japan (JP)60GEU band; cups close to EU
Germany (DE)60GEU sizing

Cup letters agree across systems up to D. Above D they diverge (a US DDD is a UK E and an EU F) which is where the size converter earns its keep. Brands that size natively in US: Natori, Wacoal, Le Mystère, Victoria’s Secret.

Fit

How to tell if 28G is your correct size

A calculated 28G is an accurate starting point. Confirm it on the body: band, cups, gore, straps.

  1. Band sits firm and level. The 28 band should be snug around your ribcage with room for two fingers, not riding up at the back. It gives most of the support.
  2. Cups fully contain the breast. No spillage over the top or sides, and no gaping or wrinkling in the G cups. Gaping usually means down a cup; spillage means up a cup.
  3. Center gore lies flat. The panel between the cups should sit against your sternum, not float away.
  4. Straps stay put. If you're tightening straps to feel supported, the 28 band is probably too big.

If the cups fit but the band is wrong, move to a sister size rather than changing cup letters. There's no universal standard between brands: a 28G in one label can fit like the size on either side in another, so use the fit checks, not just the label. Full symptom-by-symptom guide: bra fit guide.

Explore

Related bra sizes

All US bra sizes →

Reviewed for accuracy by the Brasize.ai fit team
MethodModern snug-measure standardCross-referencedUS · UK · EU · FR · AU · IT · JP · DEUpdatedJune 2026

Educational resource, not medical advice. Read our editorial policy.

Shop itAt HauteFlair, our sister retailer

HauteFlair labels cups in UK letters, so these links already convert your size by position (a US DDD lands on a UK E, a US G on a UK F). HauteFlair is owned by the same company as Brasize.ai; that relationship never changes the sizing math, charts, or fit advice on this page. How this site makes money.

Is 28G actually your size?

Don't guess from a label. Enter two measurements and get your accurate size in eight systems, plus your sister sizes.

Calculate My Bra Size →
Questions

28G bra size: answered

The questions people ask most about the 28G size: its volume, sister sizes, conversions and fit.

Is 28G a big bra size?

28G is a fuller-bust cup on a 28 band. A cup letter is a ratio, not a fixed volume: G means a 7-inch difference between bust and band, so a 28G holds more than a 28G and less than a 36G. “Big” only has meaning once you know the band.

What is the sister size of 28G?

The sister size of 28G is 30DDD (looser band); there is no snugger sister within the standard range because 28G is already at the edge of the band scale. Sister sizes hold the same cup volume as 28G on a different band. Move to one when the G cups fit but the 28 band is too loose or too tight.

What is 28G in European sizing?

A US 28G is an EU 60G. EU bands follow US × 2.5 − 10; cup letters match up to D, then EU continues the alphabet (E, F, G) where the US repeats D.

What is 28G in UK sizing?

A US 28G is a UK 28F. US and UK share inch bands and agree on cups through DD; above that US DDD = UK E, US G = UK F, US H = UK FF.

What measurements are a 28G?

Roughly a 27-inch (69 cm) snug underbust and a 35-inch (89 cm) bust at the fullest point. The 7-inch difference gives the G cup; the underbust gives the 28 band. Treat these as the center of a range.

What is 28G in centimeters?

A 28G corresponds to an underbust of about 67–72 cm and a bust of about 88–90 cm: a difference of roughly 18 cm. In metric-labelled systems the same size is EU 60G, FR 75G and JP 60G.

Which bra styles suit a 28G?

At this depth the bra is doing real load-bearing work. Prioritise full-cup and side-support constructions from full-bust specialists, firm (often three- or four-hook) bands, and wider straps. Molded single-piece cups rarely fit well here; seamed cups distribute weight and shape better. On a petite frame like a 28 band, also look for narrower wires and shorter straps: many mainstream ranges draft their wires for average frames, which is why small-band sizes can feel wide at the side even when the cup volume is right.

How do I know if 28G is my correct size?

Check four things: the 28 band sits level and snug on the loosest hook, the G cups are filled without spillage or gaping, the center gore lies flat against the sternum, and the straps stay put without carrying the weight. If the band is wrong but the cups fit, try a sister size.