Most leaks blamed on a “weak” diaper are really fit problems. Before you compare absorbency ratings, get an accurate measurement, because every brand sizes by waist and hip, and the ranges vary more than you’d expect.
Take two measurements
- Waist: measure around your natural waist, at or just above the navel, keeping the tape level and snug but not tight.
- Hips: measure around the widest part of your hips and seat.
Use the larger number when you check a size chart, and measure in the clothes you’d normally sleep in.
Why size charts disagree
A medium is not a universal size. Bumz lists its medium at 28 to 38 inches, DryBritches sizes its Posy medium at 28 to 40 inches, and LittleForBig’s medium covers 28 to 38 inches. Large ranges differ even more, so always read the chart for the exact product.
Between sizes?
DryBritches suggests going up a size if you fall between two, and that’s sound general advice for tab-style briefs: a slightly larger diaper can be tightened with the tapes, while one that’s too small will gap at the legs. The exception is if you’re very slim through the thighs, where the smaller size may seal better.
Try before you buy a case
Many retailers sell sample packs of two or three. It’s the cheapest way to confirm fit before committing to a 40- or 80-count case.
