The single biggest cause of leaks and discomfort with adult nappies isn't the product — it's the wrong size. The good news: getting the fit right takes one measurement. Here's how to choose the correct adult nappy size, from Medium to XXL.
Measure the hips, not the weight
Adult nappy sizing is based on waist and hip measurement, not body weight. Two people of the same weight can need different sizes depending on their shape, so always measure.
- Use a soft tape measure.
- Measure around the widest part of the hips and bottom, keeping the tape level.
- Note the measurement in centimetres and match it to the size chart on the product.
General size ranges
- Medium — roughly 80–130 cm
- Large — roughly 100–150 cm
- XLarge — roughly 120–170 cm
- XXL — for the largest fit; check the specific product chart
Ranges overlap on purpose. If your measurement falls in an overlap, or you're between sizes, size up for a better seal and more comfort.
Signs the size is wrong
- Too small: red marks on the waist or thighs, tabs that won't reach comfortably, a feeling of tightness.
- Too large: gaps around the legs, the nappy sliding down, leaks despite the product not being full.
A correctly sized nappy sits snugly at the waist with the leg cuffs sitting flat against the skin — no gaps.
Does style affect fit?
Yes. Tab-style diapers let you adjust the fit at the sides, which helps with in-between measurements and higher absorbency needs. Pull-ups rely on a stretch waist and work best when the measurement sits comfortably within the size range. For more on choosing between them, see our adult nappies buying guide.
Send us the hip measurement and we'll recommend a size. Call 021 691 3838 or WhatsApp us, and shop the adult range here.
Frequently asked questions
What if I'm between two sizes?
Size up. A slightly larger nappy seals better and is more comfortable than one that's too tight.
Can I mix sizes for day and night?
Many people use a higher-absorbency tab-style diaper overnight and a pull-up during the day. The size stays the same; the style changes.
How do I stop leaks if the size is right?
Check the leg cuffs are pulled out and sitting flat, and change before the nappy is fully saturated. Our guide to adult nappy care covers this in detail.
