Choosing a diaper size is less about age and more about weight and fit. Start with your baby’s current weight and pick a size where that number sits near the middle of the range. If you’re right at the top, size up—tight diapers cause red marks and more blowouts.
After fastening, the waistband should feel snug but comfortable and sit smoothly under the belly button. If you can’t slide two fingers under the waist, it’s likely too small. Check the leg cuffs next: gently “fluff” the ruffles outward. Tucked cuffs are a top cause of leaks.
If leaks happen at the back, pull the back panel higher and make sure the diaper isn’t sitting too low. If leaks happen at the legs, the diaper may be too big or the tabs may be uneven. Try a small pack in two sizes and compare which one stays drier and looks smoother after movement.
