Why Chest Measurement Is the One Number You Actually Need
Ordering clothes online without checking measurements is a gamble most people lose at least once. You know your size at one brand, you assume it carries across, and three days later you are standing in front of a package wondering who they made this for.
The fix is straightforward: get your chest measurement right, understand how garment makers express that number on a size chart, and you will almost never order the wrong size again. This guide walks through both.
For a full breakdown of sizing across all garment categories, including waist, hips, and inseam, see our Size Guide hub. This page focuses specifically on chest measurement: how to take it, how to read it, and how different garment types change the calculation.
How to Measure Your Chest
You need a soft tape measure (the kind used in sewing, not a builder's tape). If you do not have one, a length of string and a ruler work fine.
Step-by-step:
- Take your shirt off, or wear a thin t-shirt. Bulky layers will add centimetres that don't reflect your actual body.
- Stand up straight with your arms relaxed at your sides. Do not puff your chest out or pull your shoulders back artificially.
- Wrap the tape measure around the fullest part of your chest, passing it just under your armpits and across your shoulder blades. Keep it level all the way around.
- Breathe normally. The tape should sit snug against your body without digging in.
- Read the measurement in centimetres.
That is your chest circumference. This is the number you compare to "chest" or "to fit chest" columns on a standard size chart.
A few things that trip people up:
- Measure yourself, not a garment you already own. Garment measurements work differently (more on that below).
- Measure twice. Tape measures can slip. A second pass takes 20 seconds and saves a return.
- If you land between two sizes, note both. The fit section below will explain which way to go depending on the garment.
What Is a Half-Chest Measurement?
Here is where most sizing confusion starts. When a brand lists a garment size chart, they usually give a "half-chest" or "across-chest" measurement, not a chest circumference.
These two numbers are not the same thing.
Half-chest measurement is taken from the garment itself, not your body. Lay the garment flat on a surface. Measure straight across the front, from side seam to side seam, roughly 2-3 centimetres below where the sleeve joins the body. That number is the half-chest.
To convert: multiply the half-chest by two. That gives you the garment's full circumference at the chest.
Example: A t-shirt with a 52cm half-chest has a full chest circumference of 104cm. If your chest measurement is 100cm, that garment will have approximately 4cm of positive ease (room to breathe). If your chest is 104cm, it will fit with zero ease, which on an unstructured knit feels tight.
Please note: BCA aims to be as accurate as possible with our measurements, but there can be a variance of 1-5% between individual garments.
Practical rule: your chosen garment's half-chest, when doubled, should be at least 5-10cm more than your actual chest measurement for a regular fit. Less than 5cm is a slim or compression fit. More than 15cm is oversized.
Why Garment Sizing Varies Between Brands (and Countries)
There is no Australian legislative standard for clothing sizes. None. An AU size 12 at one brand is not guaranteed to be the same as an AU size 12 somewhere else, because no one is enforcing a consistent spec.
A few patterns to know:
AU sizing (including BCA's garments marked "AU") is calibrated roughly to what an Australian buyer would expect from mid-market retail. It generally runs true-to-body, with regular ease built in.
EU sizing tends to run narrower. If a garment is marked EU and converted to AU, expect it to fit smaller across the chest than the label suggests.
US sizing for women uses a different numeric system entirely. US women's sizing is not directly comparable to Australian numeric sizing, and "S/M/L" conversions vary by brand.
Age or year sizes for kids are notional. A child marked "8 years" may fit a 7-year-old who is tall or a 9-year-old who runs lean. Always check the chest cm measurement on the product page, not just the age label.
Department store sizing has crept generous over the past two decades. Designer sizing has often stayed small. BCA's sizing reflects the garment specs from our suppliers, which we display in full on each product page.
The takeaway: always check the measurement table on the product detail page, not just the size label. If in doubt, contact us before ordering. We cannot exchange for incorrect size selection.
Chest Measurement Across Different Garment Types
The same chest measurement does not produce the same fit across all garment categories. Each type has a different intended ease allowance, fabric behaviour, and construction logic.
T-shirts
A standard regular-fit t-shirt typically adds 10-15cm ease over your chest measurement. A slim-fit tee reduces that to 5-8cm. Oversized cuts often add 20cm or more, sometimes deliberately. Unisex fits generally sit between a fitted women's cut and a relaxed men's cut.
For knit fabrics (jersey, pique), the fabric stretches to accommodate. For woven fabrics, there is no give, so the half-chest measurement matters more.
Browse our blank t-shirts for size chart details on individual styles.
Polos
Polos are typically woven or structured knit (pique), with less stretch than a plain jersey tee. The placket and collar structure adds rigidity across the upper chest. Plan for the same ease you would use for a regular-fit shirt, not a t-shirt.
If you are between sizes in a polo, size up. A polo that is too tight across the chest gaps at the placket and sits awkwardly at the collar.
See our polo shirts size charts for specifics per style.
Jackets (Softshell, Puffer, Workwear)
Jackets are designed to go over a base layer. When you measure for a jacket, you need to account for what you will wear underneath.
Layering allowance: add 3-5cm to your chest measurement before checking the size chart if you will wear a shirt or light fleece under the jacket. Add 5-8cm if you plan to layer over a hoodie.
Softshell jackets sit closer to the body and have stretch panels. Puffer jackets have volume from fill but no lateral stretch. Workwear jackets (like Hi-vis) are cut for mobility over insulation layers.
Explore our jacket range for size charts per style.
Hi-vis Workwear
Hi-vis garments are subject to Australian Standard AS/NZS 4602.1, which sets requirements for reflective tape placement and background material area. To meet compliance, hi-vis garments are cut with more volume across the torso and shoulders than equivalent non-safety workwear.
This means a hi-vis shirt or vest that measures correctly for AS/NZS compliance will often feel larger than a non-safety garment in the same nominal size. Do not size down to compensate for the looser cut: the sizing is there to ensure the reflective tape sits flat and visible across the correct body zones.
If your organisation needs hi-vis for site compliance, check the AS/NZS spec requirements for your industry before ordering, and contact us if you need advice on fit for specific roles or body types.
See our high visibility clothing for full size charts.
Shrinkage: What to Allow
Cotton and cotton-rich garments shrink. The amount depends on the fabric composition and whether the garment is pre-shrunk.
Pre-shrunk cotton-rich garments: allow 1-4% further shrinkage. On a 52cm half-chest garment, that is roughly 0.5-2cm.
100% cotton garments that are not pre-shrunk: allow 5-7% extra. On a 52cm half-chest, that is 2.5-3.5cm, or roughly one size.
Children's sizing: always factor shrinkage more aggressively. Kids grow, and a garment bought close to current measurements will be too small after the first few washes.
Polyester and polyester-blends: minimal shrinkage, typically less than 1%.
To minimise shrinkage: follow the care instructions on each garment. Cold wash, low tumble or line dry. Heat is the main driver of shrinkage in cotton.
If you are ordering for a team or event and cannot afford returns, size up one step on any 100% cotton non-pre-shrunk garment.
How to Use This to Order the Right Size
Here is the practical workflow:
- Measure your chest circumference (see above). Write it down.
- Find the garment you want on the BCA website.
- Open the size chart on the product page. Most BCA product pages show a half-chest measurement table.
- Double the half-chest values to compare against your chest measurement. Find the size where doubled half-chest exceeds your measurement by your target ease (5-10cm for regular fit, less for slim, more for oversized).
- Factor in shrinkage if the garment is cotton and not pre-shrunk.
- Factor in layering if it is a jacket or outer layer.
- If you land between two sizes, size up for tops with no stretch, size to preference for stretch knits.
Still unsure? Contact us before you order. We can pull specific measurements from the garment you are looking at and help you decide. We cannot exchange for incorrect size choice, so a quick message before ordering is worth it.