Rumparooz G3 Cloth Diaper Fit & Sizing Guide: How to Get the Perfect Cloth Diaper Fit

January 30, 2026

Fuzz Rumparooz One Size Pocket Diaper

How to Achieve the Perfect Fit with Rumparooz G3 Cloth Diapers

This guide has been updated to reflect the current Rumparooz G3 One Size Cloth Diaper, which features five size settings and fits approximately 6 to 55+ pounds.

A great fit is the single most important factor in successful cloth diapering. When a cloth diaper fits correctly, it prevents leaks, stays comfortable for your baby, and performs exactly as designed.

The Rumparooz G3 One Size Pocket Cloth Diaper is designed to grow with your baby from birth through potty training using an adjustable snap rise system in a true one size design. With the G3 update, Rumparooz now offers five size settings, an expanded fit range, to comfortably fit babies and toddlers from approximately 6 to 55+ pounds.

This guide will walk you through how to achieve the perfect fit at every stage.

Rumparooz G3 Updated Sizing Overview

The Rumparooz G3 features a five-size snap rise system, which allows the diaper to grow in both width and length as your baby grows.

True One Size Fit Range: approximately 6 to 55+ lbs

Newborn: 6 to 10 lbs
Small: 10 to 17 lbs
Medium: 17 to 27 lbs
Large: 27 to 37 lbs
X-Large: 37 to 55+ lbs (fully unsnapped)

Most babies will spend the longest amount of time in the medium size setting, often from late infancy through toddlerhood. It is also very common for toddlers to briefly size up and then size back down again once they start walking and leaning out.

Cloth diapers should fit more like underwear than disposable diapers. A good fit is close to the body and snug, not droopy, hanging off the hips, or "waddling" between the legs. Bigger is not better when it comes to fit. If a one-size diaper is "sized up" too soon the diaper may appear too small due the diaper sitting incorrectly on baby's body. The diaper size should always be adjusted according to the weight chart, and the extra fabric gets "folded up" so the center of the diaper stays trim against baby and the elastic seated snugly in the natural creases of the leg referred to as the "underwear lines".

Rumparooz G3 One Size Cloth Pocket Diaper sizing chart diagram and absorbency options

Step 1: Choose the Correct Rise Setting

Rise snaps control the height of the diaper from front to back.

Start on the lowest rise for newborns.
Adjust the rise as your baby grows, always referring to the weight chart.
If the diaper looks "sloppy", gaps at the legs, or the center hangs low, it may be sized up too large.
If snaps feel strained or they keep popping open, it may be time to move up a rise.

A properly sized cloth diaper should sit at or just below the belly button, snug to the body.

Step 2: Prepare the Insert Correctly

Absorbency and fit work together.

Make sure inserts you chose are fully prepped (if they are bamboo, hemp or cotton), and the proper size for the rise setting the diaper is set to at the current time.
Take the insert in one hand and slide it in the pocket, making sure it is flat and pushed all the way to the very end of the diaper. When pulling your hand out, use the other hand to hold the end of diaper and insert (now inside the diaper) in place so the insert stays and does not slide back out of the diaper.

Insert recommendation by size:

Newborn: Microfiber 6r Soaker, Newborn insert only (stack 2 Newborn inserts for double absorbency)
Small: Bamboo 6r Soaker, Newborn insert only + Microfiber 6rSoaker Newborn Insert on top
Medium: 6r Soaker - just the One-Size or the full combo; Microfiber, Hemp, or Bamboo
Large: 6r Soaker Set - full combo with both One-Size and Newborn pieces snapped together
X-Large: 6rSoaker Set - full combo with both One-Size and Newborn pieces snapped together

The Rumparooz G3 works with all Kanga Care 6r Soaker inserts, allowing you to customize absorbency as your baby’s needs change.

Step 3: Put the Diaper On Correctly

Place the diaper under your baby with the back panel sitting at the belly button level
Holding the back in place, gently stretch the diaper forward to release the elastic tension and let the insert slide forward so it is not trapped under babies bottom.
When bringing the diaper through the legs, “cup” the diaper into a “U” or “hot dog” shape so it is cupping the center of the diaper (and the insert which is inside) around the "wet-zone”. Gently guide the diaper along the leg creases of baby's leg so the elastics sit in the natural underwear lines. The elastic should not cross over, or rest on, the meat of baby's leg near the thigh.
Once the diaper is pulled through the legs, the front will fan out flat on the abdomen. The "wings" are sides of the front part of the diaper that has the waist snaps, and they should wrap around baby's waist, above where the leg bends. The diaper should be positioned high enough that is does not restrict leg movement, or push legs into a straight position.
Next, pull the tabs on each side from the back of the diaper, wrap them around the waist to the front of the diaper, and fasten them to the front panel - snugly.

A Belly Gap

Babies change shape when they move. They are flatter when lying down and their tummy naturally fills out when they sit or stand. The diaper should be snug enough that you can’t see into the waistband, but not so tight that it presses into the belly or causes bulging. A small amount of room for movement is normal and helps keep baby comfortable without causing leaks. Once baby is upright there should not be a large enough gap to fit more that 1 finger inside the waist band.

Step 4: Check the Leg Fit and Seal

After the diaper is in place, run your finger around the circumference of the elastic, evening out the tension. The leg elastics should:

Sit in the natural crease where the thigh meets the body
No gaps and sitting smooth, not rolled in or out on itself
Not dig into the skin

If you experience consistent leaks at the legs, check sizing first before adding absorbency. Many leaks are fit-related first and absorbency related second.

Watch The Diaper Fit Videos

Common Fit Mistakes to Avoid

Sizing up too soon
Overstuffing the pocket
Neglecting to fold the extra rise fabric "up"
Assuming a bulky fit is normal for cloth diapers

A properly fitted cloth diaper should look trim, secure, and comfortable.

What’s New with Rumparooz G3

The G3 update was designed to extend fit, improve comfort, and offer three interior fabric choices.

Key G3 features include:

Five size settings for a wider growth range
Longer rise and wider wing span
Thicker back elastic for improved containment
Tummy panel for comfort and wetness protection for tummy sleepers
Laundry snap for easier storing of soiled diapers on the go
Signature patented double inner gussets for leak protection
Available interiors: Stay Dry Hypoallergenic Microchamois (original), OBV (Organic Cotton and Bamboo), and AWJ Sports Wick Jersey)