Plus Size Athletic Wear: A Complete Sizing Guide

Plus-size athletic wear requires matching your bust, waist, and hip measurements to each brand’s own chart, since sizing differs across labels.

Finding plus size athletic wear that actually fits means working with body measurements, not your standard dress size. Nike’s 1X fits different dimensions than adidas’s 1X, which is why relying on a single number across brands leads to leggings that slide down or tops that bind across the shoulders. The fix is straightforward: measure your bust, waist, and hips, then compare those numbers to each brand’s plus-size chart before you buy.

This guide walks through how to measure correctly, what the major athletic brands’ plus-size charts actually show, and which common mistakes throw off the whole process.

How To Measure For Athletic Wear

Accurate measurements are the foundation of any size chart. Use a soft tape measure and keep it horizontal the entire time—drooping tape adds inches you do not have.

• Bust: measure around the fullest part of the bust, tape parallel to the floor.
• Waist: measure around the narrowest part, usually where your body bends side to side.
• Hips: measure around the fullest part of the hips, again keeping the tape level.

Measure over bare skin or thin clothing, not bulky layers. If your numbers land between sizes, most athletic brands recommend choosing the larger size—especially for workout gear where restricted movement is a real problem.

Plus-Size Charts From Nike, adidas, And New Balance

Each brand cuts its plus-size athletic wear differently, and the size labels do not line up across companies. Here is how the three biggest athletic brands compare.

Nike’s womens plus size chart lists 1X through 3X, with 1X fitting a 45–49 inch bust and 2X a 49–53 inch bust. Nike’s official plus-size fit guide shows the full measurement ranges for every size.

adidas product labels show 1X (14W–16W), 2X (18W–20W), 3X (22W–24W), and 4X (26W–28W) for tops and jackets. Their chart lists the corresponding bust, waist, and hip ranges in inches, and the W-number conversion makes it easier to bridge from dress sizing.

New Balance handles extended sizing differently: their apparel chart runs from XS through 3XL with body measurements for chest, waist, and seat, so you compare numbers rather than hunting for a separate plus-size section.

Common Sizing Mistakes That Ruin Fit

Most sizing failures trace back to a few predictable errors, and avoiding them saves returns and frustration.

The biggest mistake is assuming your standard dress size equals your athletic-wear size. A size 16 dress does not automatically mean a 1X top from every brand, because each company’s 1X is built around different measurements. The second most common error is measuring wrong—over loose clothing or with the tape tilted, which adds inches and pushes you into a size that is too big.

Garment-specific fit differences matter too. Leggings, sports bras, and jackets each have their own fit logic even within the same size label, so read the product page notes before ordering. Some brands also distinguish regular fit from curvy fit hips, which changes the recommended size for the same person.

Fit is not just about comfort. Too-tight athletic wear restricts movement during exercise, while too-loose pieces shift and chafe. Official charts exist to prevent exactly these problems, so the ten minutes spent measuring are worth it.

When you are ready to buy, our tested roundup of the best athletic wear for plus size breaks down the top-performing pieces across brands.

FAQs

Is 1X the same as 16W?

No, not universally. adidas labels its 1X as equivalent to 14W–16W, but Nike’s 1X is defined purely by body measurements (bust 45–49 inches, waist 41–45 inches) without a W-number conversion. Always check the brand’s own chart rather than assuming a standard equation across labels.

Should I size up for workout clothes?

If your measurements fall between sizes, most athletic brands advise choosing the larger size. Workout apparel needs room for movement, and a too-tight fit restricts range of motion during exercise. Sizing up also helps if you are between two sizes on the chart rather than matching one exactly.

Do plus-size charts cover sports bras and leggings?

Sometimes, but not always. Nike and adidas publish separate charts for different garment types, since sports bras and leggings have their own fit logic beyond bust, waist, and hip measurements. Check the specific product page or its dedicated size chart before ordering these items.