Diaper Size Chart & Sizing Guide for Babies and Adults

Baby diapers go by weight. Adult briefs and pull-ups go by measurement: the larger of waist or hips. Use the charts below, or our free size finder (lb or kg, inches or centimetres).

Measuring an adult? Scroll past the baby chart to Adult diaper sizing.

Find your size in 10 seconds →
Free size finder · babies & adults · no sign-up

Baby diaper sizes by weight: quick chart

Size by weight, not age. Two babies of the same age can be two sizes apart.

These are the printed Comfees pack ranges our size finder shows. Other brands vary slightly, so check the chart on their pack.

Between two sizes?

The ranges overlap, so a 17 lb baby fits Size 2 or Size 3. Keep Size 2 while it fits with no red marks or leaks; the finder moves to Size 3 at 18 lb.

When to move up a size

• Red marks or dents on the thighs or tummy once the diaper comes off
• Tabs can't reach the middle of the waistband without stretching
• The diaper no longer covers the whole bottom
• Two fingers won't slide comfortably under the waistband
• Leaks or blowouts keep happening, even when it's fastened properly

Adult diaper sizing: how to measure

Skip pant or dress size; it rarely matches a brief's size. All you need is a soft sewing tape and two minutes.

1. Remove bulky outer clothing. Light clothing can stay on.
2. Waist: measure just below the belly button, or wherever the tummy is widest. Snug, not tight.
3. Hips: measure around the widest part.
4. Use the larger number. Women often measure bigger at the hips, men at the waist.

Measuring a parent? Ask first, offer privacy and measure over light clothing. Remeasure after weight changes or swelling.

Adult diaper sizes (inches and cm)

Go by the larger of the waist or hip measurement. These are the ranges our size finder uses:

Right on a line? The size finder picks the larger size. Within a few inches of one? Check the brand's own chart too, because brands draw their lines differently:

• TENA runs about 2–4" higher. Its Medium goes up to 47", and its Large starts at 48".
• TENA and Attends move to 3XL above about 70".
• Pull-ups often use different ranges from tab briefs, so for pull-up underwear always check the chart on the pack.

Pull-ups or tab briefs? Pull-ups suit people who are up and about; tab briefs are easier to change for someone lying down. Compare them in adult pull-ups vs tab-style briefs.

Adult absorbency: light, heavy or overnight

A bigger brief isn't necessarily more absorbent. Size is about fit; absorbency is about capacity.

• Leaks while still mostly dry? Check the fit.
• Leaks only once it's full? Move up in absorbency, not size.

The size finder offers three absorbency levels:

• Light–moderate: dribbles or small, occasional leaks during the day, with regular bathroom trips. Shows pull-up protective underwear first.
• Heavy: larger or more frequent leaks. Shows tab-style briefs first.
• Overnight: the most capacity, for long stretches in bed. Shows overnight briefs first. See the best overnight adult diapers in Canada.

On the pack, check the droplet scale (more drops, more capacity) or names like Plus, Super, Ultra or Maximum.

Need a little extra?

• A booster pad sits inside a brief or pull-up. With no plastic backing, it absorbs first and lets overflow into the product beneath.
• Never wear a booster pad alone or in regular underwear, and never tuck a plastic-backed pad inside a brief.

The four-point fit check

Even the right size leaks if it goes on in a rush. Check these on a baby or an adult:

1. Leg cuffs out. Ruffles sit outside, with no gaps at the legs. Gaps usually mean too big or not pulled snug.
2. Waistband placed right. Adults: about hip-bone height, snug in the groin. Babies: just below the belly button.
3. Tabs angled up. On adult briefs, tabs point slightly upward and sit forward on the hips; tabs that overlap in the centre mean it's too big. On babies, tabs sit evenly on both sides.
4. No red marks. Snug, not tight: two fingers under a baby's waistband, a flat hand under an adult's at the tummy. Red marks mean too small or too tight.

Using the size finder

Enter a baby's weight (lb or kg), or an adult's larger measurement (inches or cm) plus an absorbency level. You'll see the size, its printed range and matching products at Canadian prices.

Want the detail behind these charts? Read our full baby and adult diaper size chart guide.

Still not sure?

Try the first few diapers of a new size before you stock up. Our team is happy to help: contact us with your baby's weight or the waist and hip measurements.

More reading: our Canadian buyer's guide to adult diapers, or browse all incontinence products.

General sizing information, not medical advice. If skin looks sore or broken, or incontinence is new or suddenly worse, talk to a doctor, nurse or pharmacist.

Find your size in 10 seconds →
Free size finder · babies & adults · no sign-up

Brand size charts: why a Medium isn't always a Medium

Every brand sizes a little differently. A 42-inch hip is a Medium on our general chart, but a Large in Depend underwear and M/R or L/XL in TENA briefs. Before you switch brands, check the brand's own chart below. These are the manufacturers' official charts, collected in October 2026; the chart printed on the pack always wins.

Baby diapers and training pants (by weight)

Adult briefs and protective underwear (by waist or hips)

Not sure? Use the size finder on our home page, or call us at 365-797-2167.