Kids Bottoms Buying Guide: Sizes, Styles and Stretch

Quick answer

Buy kids bottoms by current measurements, not age or the size your child wore last season. Prioritize a soft, stretchy waistband and a fit that leaves room to move, then size up only when the next size still stays put. For everyday wear, start with leggings and a simple tee, and use bloomers for babies who need nappy room.

Kids grow at wildly different rates, so a kids bottoms buying guide that only lists age ranges will let you down. The better approach is to measure once, choose a style that matches how your child moves, and check the stretch before you commit.

This guide walks through children's bottoms sizes, the main kids bottoms styles, and the fit checks that prevent waistbands from digging in or hems from dragging. It also covers how to judge stretch in leggings, bloomers, and tops so you can buy with confidence.

Start with measurements, not age

Age labels are a starting point, not a guarantee. Two children the same age can differ by two sizes, especially through the toddler years. Measure your child's waist at the narrowest point and their hip at the fullest point, then compare those numbers to the brand's size chart rather than assuming a 3T fits like the last 3T you bought.

If you are between sizes, think about how the garment is worn. For leggings and pants that need to stay up during play, choose the size that matches the waist and accept a slightly shorter length. For loose styles like bloomers, the roomier size is usually the safer pick because the elastic does the holding.

• Measure waist and hip, then check the size chart before ordering.
• If waist and hip point to different sizes, follow the waist for fitted bottoms.
• Re-measure before each seasonal shop, not once a year.

Match the style to the movement

Leggings suit crawling, climbing, and layering under dresses. Look for a ribbed cuff at the ankle, which keeps the hem from riding up, and a full-length, loose-fitting cut that does not restrict the knees. A three-pack in one colour and size keeps the morning routine simple and gives you a spare when one pair is in the wash.

Bloomers are the practical choice for babies in nappies. A roomy fit with elastic at the legs and waist allows for the nappy without pinching, and the shape stays comfortable when your baby sits or rolls. For tops, a boxy fit with cap sleeves and vintage-style ribbing at the neck moves easily over the head and layers under cardigans.

• Choose leggings for active play and layering.
• Choose bloomers for nappy room and easy changes.
• Choose a simple tee for everyday tops that layer well.

Check stretch and fabric honestly

Stretch comes from two places: the knit and the elastane content. A cotton-and-elastane blend gives you recovery, so the waistband returns to shape after a day of wear. If a product page does not list fibre content or available option types, treat that as missing information and ask before buying rather than guessing.

Plant-based dyes can vary slightly between batches, so do not expect an exact colour match across separate orders. That is normal for naturally dyed cotton, and it does not affect fit or softness. What matters more is whether the fabric feels soft against skin and whether the waistband has enough give to pull on without a struggle.

• Look for a stated elastane percentage if you need stretch recovery.
• Expect slight colour variation in plant-dyed pieces.
• If fibre content is not listed, ask before you buy.

Fit checks before you commit

Do a squat test: if the waistband gaps at the back when your child bends, the size is too big or the rise is wrong. Do a pull test at the ankle cuff: if it leaves a red mark after ten minutes, the cuff is too tight. For bloomers, check that the elastic sits flat against the leg without cutting in when your baby is seated.

Length matters too. Full-length leggings should reach the ankle without bunching, and hems should not drag on the floor. If your child is between lengths, a slightly cropped look is safer than a hem they will trip over.

• Squat test for waistband gaping.
• Ten-minute check for red marks from cuffs.
• Hem should clear the floor when standing.

Decision rules for buying kids bottoms

• If your child is between sizes: Follow the waist measurement for fitted bottoms and size up for loose styles like bloomers. Waist fit decides comfort; length can be adjusted later.
• If the waistband leaves marks: Size up or switch to a style with a softer, wider elastic rather than stretching the current pair. Red marks mean the fit is wrong, not that your child needs to get used to it.
• If you need stretch that recovers: Choose a fabric with a stated elastane content, such as 95% organic cotton and 5% elastane. Recovery matters more than initial softness for active kids.
• If you are buying for a baby in nappies: Pick bloomers with elastic legs and a roomy fit so the nappy has space without gaping. Room to grow beats a snug fit at this stage.
• If the product page is missing details: Check for fibre content, available sizes, and colours before ordering; ask if they are not listed. Missing specs are a reason to pause, not to guess.

Product facts that help you decide

• 3 Pack of Kids Leggings: Pack includes 3 Leggings in your choice of colour and size. Full length, loose fitting pants with a ribbed cuff at the ankle, crafted in NICO's classic GOTS certified cotton. The ribbed cuff keeps the hem in place during play, and the three-pack means fewer laundry emergencies.
• 3 Pack of Baby Bloomers: Pack includes 3 bloomers in your choice of colours, with elastic legs and waist and a roomy fit to allow for nappy. The roomy cut and elastic waist make changes easier and reduce pinching for babies in nappies.
• Kids Tee: Boxy fit tee with vintage style ribbing at the neck and a cap sleeve, crafted in NICO's classic GOTS certified cotton. 95% organic cotton, 5% elastane. The elastane gives the tee enough stretch to pull over the head comfortably while keeping its shape.

Who this guide is for

Best for

• Parents buying everyday leggings, bloomers, and tees for active kids
• Caregivers who want a simple, measurement-based approach to children's bottoms sizes

Not for

• Shoppers looking for formal or occasion wear
• Anyone who needs performance or technical outdoor gear

Measure first, match the style to how your child moves, and check stretch before you buy. A soft waistband and a hem that stays put will do more for comfort than any size label.