38G and 38H share the same 38-inch band — 38H simply holds more cup volume than 38G, roughly one letter-step's worth of extra bust measurement.
38G and 38H share the same 38-inch band — 38H simply holds more cup volume than 38G, roughly one letter-step’s worth of extra bust measurement.
38G vs 38H: same band, different cup — here’s exactly how much more volume 38H actually holds.
Why 38G and 38H Only Differ in Cup Volume
On the same band, a bigger cup letter simply means more distance between your underbust and bust measurement — nothing about band comfort or ribcage size changes.
Which One Should You Try
If you’re between the two, cup gaping or wrinkling at the top usually means the smaller cup, while visible spillage at the top or sides points to needing the bigger one.
Not sure which is your actual size? Run your measurements through the Main Bra Calculator — free, private, under a minute.
A Quick Self-Check
Put on your current bra and raise both arms straight overhead — if the band shifts up noticeably or a cup gaps open, that’s a real clue pointing to which of the two sizes you actually need.
A Real Example
Someone wearing a smaller letter who feels persistent cup gaping or gets red marks from an underwire pressing into tissue is a textbook case for sizing up to the bigger letter.
A Mistake Worth Avoiding
Buying based on the number alone without trying the style — construction varies enough between brands that the same labeled size can fit two completely different ways.
When This Comparison Actually Comes Up
This is also relevant after any real body change — pregnancy, significant weight change, or just time — since old assumptions about “my size” stop being reliable exactly when this kind of precise distinction matters most.
Brand Cut Changes the Answer Too
Seam placement inside the cup changes how volume actually sits — a seamed cup with more panels can mold to an individual shape more precisely than a single molded cup, which matters more at some sizes than others.
Style Considerations
Balconette and demi styles tend to work well here since they don’t rely on excess fabric to create shape.
This Can Change Over Time
If you’ve changed your exercise routine significantly, muscle and tissue distribution can shift enough to affect band fit specifically, even without a change in overall weight.
Shopping Tips
Reading recent reviews that mention true-to-size feedback for the exact style (not just the brand generally) is one of the more reliable ways to predict fit before buying online.
FAQ
Start with whichever feels closer to your current bra's fit — cup gaping means try smaller, spillage means try bigger.
No — cut and construction vary by brand, so always check a new brand's own chart rather than assuming your usual size carries over exactly.
Yes — even a single cup letter on the same band represents a real, measurable volume difference, not a marginal one.
No — the relationship between 38G and 38H (one cup-letter step on the same band) works the same way at any band size.
Often yes — sports bras use different construction (more compression, less structured cup shaping) that can make the same labeled size feel noticeably different from an everyday style.
Yes, for most people — weight change, age, hormonal shifts, and even different laundry habits can all move the number gradually, which is why periodic re-measuring matters more than getting it right once.
Mid-morning to early afternoon tends to be most representative for most people — very early morning or late evening can show minor temporary swelling that isn't your typical baseline.
