One of the biggest frustrations of online activewear shopping is sizing inconsistency. A medium in one brand might fit like a large in another. The solution? Taking accurate body measurements and learning to interpret size charts correctly. This guide walks you through the process step by step.
Why Measurements Matter More Than Size Labels
Size labels (S, M, L, XL) are essentially meaningless without context. There's no universal standard governing what these labels mean, so each brand defines them differently. A "medium" from an American brand may correspond to a "large" from an Asian manufacturer or a "small" from a European label.
Your body measurements, however, are objective and consistent. When you know your chest measures 102cm, you can compare that against any brand's size chart to identify the appropriate size—regardless of what label they assign to it.
Keep your measurements saved on your phone. You'll reference them frequently when shopping online, and body measurements change slowly enough that annual updates are typically sufficient.
Tools You'll Need
Before starting, gather these items:
- Flexible measuring tape: The soft, fabric kind used for sewing. Hardware store metal tapes don't wrap around your body properly.
- Mirror: To ensure the tape is positioned correctly and level.
- Form-fitting clothing or underwear: Measuring over bulky clothing skews results.
- Paper and pen: Or your phone, to record measurements immediately.
If you don't have a measuring tape, a piece of string and a ruler works in a pinch—wrap the string, mark where it meets, then measure against the ruler.
Essential Measurements for Tank Tops
Chest Measurement
The most important measurement for tank tops is your chest circumference. This determines how the garment fits across your broadest upper body area.
How to measure: Stand straight with arms relaxed at your sides. Wrap the measuring tape around the fullest part of your chest, typically across the nipple line for men or across the fullest part of the bust for women. The tape should be snug but not tight—you should be able to slip a finger underneath. Keep the tape parallel to the floor; use a mirror to verify it hasn't slipped down in the back.
Waist Measurement
While less critical for tank tops than for bottoms, waist measurements help with longer tanks and those designed for a fitted silhouette.
How to measure: Find your natural waist—the narrowest part of your torso, usually just above the belly button. Wrap the tape around this point, keeping it parallel to the floor. Don't suck in your stomach; measure while breathing normally.
Length Considerations
Tank top length varies significantly between styles. If you prefer longer or shorter fits, measure from the base of your neck (where it meets your shoulder) down to where you want the hem to fall.
Standard tank top lengths typically fall 5-8cm below the waistband of pants. Longer "longline" styles extend 10-15cm below. Cropped styles end at or above the natural waist.
- Chest: Around fullest part, tape parallel to floor
- Waist: Around natural waist (narrowest point)
- Length: From shoulder/neck junction to desired hem
- Record in both centimetres and inches for flexibility
Understanding Size Charts
Every reputable clothing brand provides a size chart. Learning to read these charts correctly is essential for online shopping success.
Body Measurements vs Garment Measurements
This distinction trips up many shoppers. Body measurement charts show the physical dimensions the size is designed for. Garment measurement charts show the actual dimensions of the clothing item itself.
Body measurement example: Size M fits chest 96-102cm. This means if your chest measures within that range, size M should fit you.
Garment measurement example: Size M chest width 52cm. This is the actual width of the garment laid flat. Double it (104cm circumference) to compare against your body measurement—though garments are typically slightly larger than body measurements to allow movement.
Fit Allowances
Clothing isn't meant to be skin-tight (unless it's compression wear). Brands build in "ease" or extra room for comfort and movement. Regular fit tank tops typically add 5-10cm to body measurements. Slim fit adds less; loose fit adds more.
When comparing your measurements to a size chart, don't expect exact matches. If your chest is 100cm and the size M range is 96-102cm, you're solidly within range even though 100 doesn't equal 96 or 102.
What to Do When You're Between Sizes
If your measurements fall between two sizes, several factors help determine which direction to go.
Consider the Fit Style
For regular or loose fit styles, sizing down often works fine because the extra room is already built in. For slim fit or compression styles, size up to avoid uncomfortable tightness.
Consider the Fabric
Fabrics with higher elastane content (5%+) accommodate being between sizes better than rigid fabrics. If in doubt and the fabric has good stretch, you have more flexibility.
Consider Your Preference
Do you prefer your workout clothes snug or relaxed? Your personal comfort preference should influence between-size decisions.
If you can't decide between sizes and the item can't be easily returned, size up. A slightly loose tank top is wearable; one that's too tight is uncomfortable and unflattering. You can always layer a larger size over other clothing.
Brand-Specific Considerations
While measuring yourself is universal, certain brand tendencies are worth knowing.
Athletic Brands (Nike, Under Armour, Adidas)
Performance brands often run slightly smaller than casual brands because they're designed for closer-to-body fits. Consider sizing up if you're between sizes or prefer a relaxed fit.
Asian-Manufactured Brands
Brands manufactured primarily for Asian markets often run one size smaller than Australian/US sizing. Always check the specific size chart rather than assuming your usual size.
Budget and Fast Fashion
Sizing consistency tends to be poorer in budget brands. When purchasing inexpensive items, consider ordering multiple sizes if returns are free.
Measuring for Online Purchases
Use the Brand's Own Size Chart
When buying from a specific brand, use their size chart—not a general guide. Each brand's chart reflects their actual garment dimensions.
Check Customer Reviews
Reviews often mention fit. Comments like "runs small, size up" or "true to size" from multiple reviewers provide valuable real-world guidance.
Compare to Items You Own
If a brand provides garment measurements, measure a tank top you already own that fits well. Comparing these measurements to the brand's chart helps predict fit accurately.
Re-Measuring Over Time
Your body changes. Weight fluctuations, muscle gain or loss, and natural aging all affect measurements. Consider re-measuring:
- Annually, as a routine practice
- After significant weight changes (5kg+)
- If you've been strength training consistently for several months
- Whenever recently purchased clothes fit differently than expected
Accurate measurements are your best tool for online shopping success. Take five minutes to measure yourself properly, save those numbers, and reference them every time you shop. The reduction in returns and disappointments makes this small investment worthwhile.