Size Chart & Measuring Tips

How Do I Choose the Right Size?

We know it's not news to you, but girls don’t grow to a template. One minute your girl's BFF - who was once her same height - might all of sudden rock up to your place a head taller or you run into a friend she had play dates with in preschool and she's burst into full blown curves. And then there's your own tween or tween - one minute she's all limbs, the next she’s filling out — and the in-between? It can feel (really) awkward.

That’s why we design our periodwear to flex with real, changing adolescent bodies — whether she’s got narrow hips, long legs, or she's hit curves early.

Choosing the right fit shouldn’t be a guessing game. To make sure it's not, you'll find that this page is packed with fit tips and sizing info to give you the best chance of landing the right style, first time.

SIZE CHART

Drag slider left for cm / right for in

CENTIMETRES

INCHES

How to Measure Her (Without Guesswork)

All you need is a soft tape measure (or string + ruler) and a minute or two.

Here’s how to measure the areas we list in the size chart... written with growing bodies in mind.

This is her natural waist — the narrowest part of her middle.

👉 You’ll usually find it just above the belly button.

This is the top of the hip bones — where mid-rise undies naturally sit.

👉 On growing girls, it may be 5–8cm (2-3.25in) down from the waist, depending on her shape.

👉 Feel for the bony ridge just below the waist (aka the top of the pelvic bone) — that’s the spot to measure around.

This is the widest part of her hips and bottom.

👉 Stand side-on in a mirror and measure around the fullest part of her bum and hips, using the mirror helps you to keep the tape level all the way around.

Fitting Troubles? Try This

We get it — tweens and teens come in all shapes, and sometimes size charts don’t tell the full story.

If she’s sitting between two sizes on our chart, here’s a trick that works 98% of the time:

➡️ Grab her favourite pair of undies — ideally something similar in style to the Eltees you have in mind. They should be fairly new so they haven't lost stretch or shape.

➡️ Lay them flat and measure across the waistband from side seam to side seam. This is called the half measure.

➡️ Compare that number to the half measure column in our size guide.

If the undies you’re measuring are starting to feel snug, it’s probably time to size up.

Also, avoid the urge to do the 'go bigger so she can grow into them' thing. It's imperative that they don't gape at the leg opening to ensure they don't leak.

✨ Extra Fit Tips:

Use a soft measuring tape and ideally measure over undies or a close-fitting layer.
It’s normal for waist and hip proportions to feel “off” during growth spurts. In those instances, you're best to use the half measure.
If she’s between sizes, or if her go-to undies are starting to feel tight, size up. Especially if you're buying UnderSwim (OG or G-Fit) as they are a firm fit.

Still unsure?

Send us her usual brand and size, plus your flat measurement, and we’ll take it from there.

We know our fits better than anyone — and while we can't guarantee we'll hit the mark every time, we do have an excellent strike rate. 👑

The Tee (Eltee Sydney Blog)

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