BRABAR vs. Victoria's Secret, SKIMS, Aerie, and ThirdLove: How Bra Sizing Methods Compare

BRABAR measures the rib cage directly, with no added inches, for band size in sizes 28-38 and cups AA-DDD/F. Victoria's Secret measures higher on the torso near the armpit. SKIMS' published instructions describe direct measurement, but its actual calculator output tells a different story — more on that below. ThirdLove's own guidance has used more than one add-inches formula in recent years before its current instructions moved to direct measurement. Aerie's own instructions also describe a direct measurement, but third-party fit guides and customer reports consistently note its charts run large in the band relative to a pure direct measurement. Five brands, five outcomes for the same body - here's exactly where each one measures, and why it matters most for anyone with a small band or a full bust.

Why the Same Body Gets Five Different Sizes

Bra size is only two numbers: a band size and a cup letter. But where a brand measures the band, and whether it adds anything to that number before assigning a size, changes the result more than most shoppers realize. A person with the exact same rib cage and bust measurement can be told she's a 28DD at one brand and a 32A at another - and both brands would say they measured her correctly.

Quick Comparison Table

BRABAR vs. Victoria's Secret

Victoria's Secret's published fitting instructions direct shoppers to measure higher on the torso, bringing the tape under the arms and across the back near where the straps meet the cups - above the bust rather than directly beneath it. Because the body is wider at that point than at the rib cage, this measurement point tends to produce a larger band number for the same person. BRABAR measures directly under the bust, at the rib cage, where the band actually sits and does its job. See our full breakdown in BRABAR vs. Victoria's Secret: Why Where You Measure Matters.

BRABAR vs. SKIMS

SKIMS' own size guide instructs customers to measure the underband and overbust directly and round to the nearest whole number — a reasonably direct approach on paper. Its actual calculator tells a different story: entering a 32-inch band and 38-inch bust returns a size of 36B, not the 32DDD/F a direct rib-cage calculation would produce. Working backward, that result matches the classic plus-4 formula exactly — 4 inches added to the true 32-inch band to get the labeled 36, with the cup then calculated against that inflated band number rather than the real one. The written instructions and the actual output don't match. Separately, for general reference: this kind of offset also isn't always flat across a size chart — many bra size charts across the industry add more inches at the smallest bands and taper toward a smaller addition, or none at all, by a 40 band. The clearer, structural difference from BRABAR is range: SKIMS' band-and-cup bra styles start at a 30 band, while BRABAR carries true 28 bands built specifically for smaller rib cages, which is exactly the size range most mainstream brands, including SKIMS, don't reach.

BRABAR vs. Aerie

Aerie's own instructions describe measuring directly under the bust. In practice, however, third-party bra fit guides and customer reviews consistently report that Aerie's bras run large in the band, often recommending shoppers size down a full band from their raw measurement — and Aerie customers have directly and publicly asked the brand why its chart still resembles the older "plus-4" style of sizing despite the direct-measurement instructions. Whatever the cause, the practical result for the shopper is the same pattern we've documented elsewhere: a size that doesn't match a direct rib-cage measurement. BRABAR's EZ-fit method uses the rib cage number as the band size with nothing added, so the size you measure is the size you buy.

BRABAR vs. ThirdLove

ThirdLove is well known for its half-cup sizing - a genuinely useful innovation for anyone who falls between standard cup letters. Its measuring methodology has changed more than once over time, even as its actual bra styles and construction have not: some of ThirdLove's own published guidance has instructed adding as much as 4 inches to the underbust measurement, other more recent guidance instructed 2 to 3 inches, and its current core measuring instructions have moved to a direct rib-cage measurement with nothing added at all. The formula changed; the physical bras being measured for didn't. That's the same pattern showing up at SKIMS — a brand's written instructions and its actual sizing output can tell two different stories, no matter which formula it happens to be using in a given year. Where ThirdLove and BRABAR diverge most is at the smaller end specifically: BRABAR's range starts at 28, serving the smaller-band, fuller-bust proportion that ThirdLove and most other adult-oriented brands still don't reach. ThirdLove is also designed for adult women; BRABAR is built specifically for the teen and junior body, which is narrower and shaped differently than a fully mature adult frame even at the same band measurement.

BRABAR vs. Pepper

Pepper is one of the few brands built specifically for smaller busts (AA-B cups), and its fit guide instructions describe a direct underbust measurement. But its published size chart tells a different story once the numbers are checked against each other - details are in our full comparison, Why Your Band Size Isn't What You Think It Is.

A Wider Industry Shift Toward Direct Measurement

Look across these five brands and a pattern emerges: multiple companies' own written instructions have moved toward describing a direct rib-cage measurement, even where the actual calculators or resulting charts haven't fully caught up yet. ThirdLove's core measuring guidance has shifted away from its own earlier add-inches formulas toward the same direct method BRABAR has used from the start. This lines up with a broader, longer-standing precedent: international sizing standards, including a European regulation dating to 1975, have defined band size as the direct underbust measurement rather than a measurement with anything added. BRABAR didn't invent direct measurement — the anatomical logic and the international precedent both predate the brand. What BRABAR has done is apply that standard consistently, without exception, since day one, across a size range other brands still don't reach, and make it the explicit foundation of a public measuring method rather than a footnote. As more of the industry's own instructions drift toward the same direct approach, that's a sign the standard BRABAR has built around all along is the direction the category is heading — even if actual output, as SKIMS shows, doesn't always match the instructions yet.

What Makes BRABAR Different Across the Board

• No added inches, ever, and no history of adding them. BRABAR's EZ-fit rib cage method uses your direct underbust measurement, rounded to the nearest even number, as your band size - full stop, and always has.
• The widest small-band range. Band sizes from 28 to 38, specifically because the 28-30 range is where most other brands, from mass retailers to specialty small-bust labels, stop short.
• Built for developing bodies, not just smaller adult ones. BRABAR designs specifically for teen and junior proportions - narrower rib cages, closer-set busts, and frequent size changes - rather than scaling down an adult pattern.
• Cup range from AA to DDD/F. Full support across the proportions a small band with a full bust actually needs, not just the smallest cup letters.
• Founded on a real, documented gap in the market. BRABAR's founder, a 20+ year intimates industry veteran, started the brand after being unable to find a properly fitting bra for her own teenage daughter using any existing brand's method.

How to Check Any Brand's Method for Yourself

You don't have to take any brand's word for it, including ours. Measure your own rib cage directly, underneath the bust, and round to the nearest even number. That's your band size under the rib cage method. Then check any brand's calculator: does it assign you that number, or one that's noticeably larger? A gap of four or five inches between your direct measurement and the assigned band means that brand is layering something on top of the raw number - whichever specific method it calls it and whatever its written instructions claim.

Frequently Asked Questions

Which bra brand has the most accurate sizing method?

Accuracy depends on where a brand measures the band and whether it adds inches to that measurement. BRABAR measures the rib cage directly with nothing added. SKIMS and Aerie's written instructions describe direct measurement, but their actual calculator output and customer-reported results consistently show a band size larger than a direct measurement would produce. Victoria's Secret measures higher on the torso by design.

What is the smallest bra band size available?

Band size availability varies by brand. BRABAR carries true 28 bands. SKIMS, Aerie, and ThirdLove all start at a 30 band. Victoria's Secret's standard range typically starts around 30 as well.

Why does my Victoria's Secret size differ from my BRABAR size?

Victoria's Secret's fitting instructions measure higher on the torso near the armpit, which tends to produce a larger band number than a direct rib-cage measurement, since the body is wider at that point than directly under the bust.

Does SKIMS use the plus-4 method?

SKIMS' written instructions describe a direct underbust measurement, not an explicit plus-4 method. However, testing SKIMS' own calculator with a 32-inch band and 38-inch bust returns a size of 36B — not the 32DDD/F a direct measurement would produce. That result matches a plus-4 formula exactly: 4 inches added to the true band, with cup size then calculated against the inflated number.

Does the added-inches offset stay the same across every band size?

Not always. For general reference, many bra size charts across the industry add more inches at the smallest bands and taper down to a smaller addition, or none at all, by the time the chart reaches a 40 band.

Has ThirdLove always measured the rib cage directly?

No, and its formula has changed more than once. Different pieces of ThirdLove's own guidance have instructed adding as much as 4 inches to the underbust measurement, and separately 2 to 3 inches, before its current core instructions moved to a direct rib-cage measurement with nothing added. The bras themselves didn't change across these shifts, only the formula used to size for them.

Is the industry moving toward direct rib-cage measurement?

The written instructions from several major brands, including ThirdLove's current guidance, have moved toward describing a direct underbust measurement rather than an add-inches formula, aligning with the same anatomical approach BRABAR has used since its founding. Actual calculator output doesn't always match those instructions yet, as SKIMS demonstrates, but the direction of the written guidance is notable.

Is there a bra brand designed specifically for teens with small bands and full busts?

BRABAR is built specifically for this proportion, with band sizes from 28 to 38 and cups from AA to DDD/F, designed around teen and junior body proportions rather than scaled-down adult patterns.

Find your accurate size with BRABAR's Fit Guide and Bra Size Calculator, and explore the full range of band and cup sizes, built around the rib cage method from the ground up.