Onesies come in a variety of sizes for men, women, juniors, children, and babies. Choosing the right size can be difficult, especially if you’ve never purchased a onesie before. Our comprehensive size guide will help you determine how to find the best fit. How do I choose the right size for my onesie?

Size chart recommendations provide a loose and baggy fit, therefore sizes run big. For females between sizes we recommend sizing down. For males between sizes we recommend sizing up. Costumes Onesies are one size fits most - up to 6'2"" and 225lbs.

Item-specific measurements are listed in inches SIZE LENGTH CHEST SLEEVE 0-3M 14.25 5.875 7.375 3-6M 15.5 6.5 7.75 6-9M 16.25 6.875 8.125 9-12M 17 7.25 8.5 12-18M 18 7.625 8.875 18-24M 19 8 9.25

With our onesie size calculator, you can quickly and easily determine the perfect size for yourself or your little ones. Whether you’re buying a cozy onesie for lounging or a fun gift for a loved one, this guide will help you understand the results and make sure you get the best fit.

Use our detailed size chart to ensure you select the right size for every garment. Our easy-to-follow measurements and conversion charts help you find the perfect fit for maximum comfort and style.

Up to 16 Ibs. / Up to 7.3 kg.

Grab a tape measure, write down the measurements and compare with our size chart for the right size.

How to measure To choose the correct size, measure as follows: Width Measure around the fullest part, from underarm to underarm. Length Measure from the top of the neck to the bottom.

Please ensure you select the correct size when placing your order. If you are unsure of your size, please email us or SIZE UP. Due to a high volume of orders, we are unable to change your size after your order has been placed.

If you have any questions, feel free to give us a call and we are more than happy to help find the best size for your baby or toddler. Notes – Conversion: 2.45cm = 1 inch | All measurements are approximate due to ironing and fabric stretch taken into account.