THE ONU SIZE & FIT GUIDE

Find Your Perfect Fit ♡

At Onesie Nation USA, we believe confidence starts with the perfect fit. Our collections are designed to celebrate your shape, embrace your curves, and keep you looking and feeling your best.

Whether you’re shopping our signature bodysuits, cozy onesies, or statement two-piece sets, we’re here to help you find your fit.

WOMEN’S SIZE CHART

Use the following chart as a general sizing reference. Measurements are in inches and refer to your body, not the garment.

Size	Bust	Waist	Hips
XS	31–33	24–26	34–36
S	34–36	27–29	37–39
M	37–39	30–32	40–42
L	40–42	33–35	43–45
XL	43–45	36–39	46–49
2X	46–49	40–43	50–53
3X	50–53	44–47	54–57

This is a general reference chart. Fit and available sizes may vary depending on the collection, fabric, and garment construction. Always review the individual product description.

AVERAGE & TALL GIRL FRIENDLY ♡

We know that one length doesn’t fit everybody!

Select ONU collections are available in two inseam options:

AVERAGE LENGTH — 30” INSEAM

Designed for customers who prefer a standard-length fit.

TALL LENGTH — 37” INSEAM

Designed for customers who love extra length, longer legs, or a dramatic stacked or flared look.

Please note: Inseam measurements refer to the inside leg length, from the crotch seam to the bottom hem. They do not represent your total height.

Inseam options vary by collection. Always confirm the available length before purchasing.

HOW TO MEASURE YOUR BODY

Bust: Measure around the fullest part of your bust, keeping the measuring tape level.

Waist: Measure around your natural waistline, typically the narrowest part of your torso.

Hips: Measure around the fullest part of your hips and buttocks.

Inseam: Measure from the top of your inner thigh to your desired pant length.

For the most accurate fit, use a soft measuring tape and measure while wearing lightweight clothing.

FIND YOUR ONU FIT

BODYSUITS & ONE-PIECE COLLECTIONS

Our bodysuits are designed to complement your natural shape.

Depending on the collection, fabrics may offer stretch, compression, or a sculpted fit.

For a comfortable fit, we recommend selecting your size based on your bust, waist, and hip measurements.

If your measurements fall between two sizes, consider the garment’s stretch level and your preferred fit before selecting a size.

TRACKSUITS & TWO-PIECE SETS

Our two-piece collections are designed to combine comfort with standout style.

Some styles feature fitted tops, flared pants, stacked legs, or relaxed silhouettes.

If your upper and lower body measurements fall into different sizes, refer to the specific collection’s fit notes before ordering.

WRAP TOPS & LAYERING PIECES

Our wrap tops and layering pieces are designed to complement your ONU outfits.

Please check each product description for available sizes, fabric stretch, and styling recommendations.

UNDERSTANDING THE FIT

Sculpted Fit: Designed to follow the body’s natural shape.

Compression Fit: A firmer, more supportive feel depending on fabric and construction.

Relaxed Fit: A comfortable silhouette with additional room.

Flared Fit: Fitted through the upper leg with a wider opening toward the hem.

Stacked Fit: Extra pant length designed to gather around the ankle or footwear.

BETWEEN SIZES?

We recommend reviewing your measurements, the fabric composition, and the fit description before ordering.

For styles with less stretch or a snug fit, sizing up may provide additional comfort.

For highly stretchy styles, your usual size may be appropriate depending on your preferred fit.

IMPORTANT SIZING INFORMATION

• Sizing may vary between collections.
• Not all styles are available in every size.
• Average and Tall options are offered only on select items.
• Fabric stretch and compression can affect how a garment fits.
• Product measurements may vary slightly due to manufacturing tolerances.
• Please review all product descriptions before purchasing.

FINAL SALE REMINDER

Due to the intimate nature of our onesies, bodysuits, and select apparel, these items are final sale, except where required by law or when merchandise arrives damaged, defective, or incorrect.

Please select your size carefully before checkout.

NEED HELP CHOOSING YOUR SIZE?

We’re happy to help you find your ONU fit!

Visit www.onesienationusa.com and select Contact Us to submit a sizing question.

For the best assistance, include the product name, your bust, waist, and hip measurements, your preferred fit, and the inseam option you’re considering.

Our team can offer sizing guidance, although an exact fit cannot be guaranteed.

Made for your shape. Styled for your confidence. Welcome to The Nation. ♡