Kinderpack comes in four basic sizes: infant, standard, toddler and preschool. These sizes refer to the body sizes. You can also order carriers with two different strap lengths: standard and plus. You may also see petite strapped KP's if you are buying in the second-hand market. With addition of Perfect Fit Adjusters (PFA's), Melissa no longer carries petite straps. PFA's can reduce the strap length to one size lower. That means that plus straps can be cinched down to be standard length and standard length can be cinched down to petite.
So, how do you know what size to buy? General guidelines can be found on the kindercarry website (http://kindercarry.bigcartel.com/carrier-info). To assist with sizing help, we took photos of three different children in all four sizes! Except for the infant size, all of the pictured carriers have plus straps.
Our first "model" is Spencer. He is 16 months old, 27 inches tall and 25 lbs. I usually wear Spencer in a standard size Kinderpack. An infant size would also still be appropriate for him to wear. He isn't completely knee-to-knee but is well-supported. Toddler and preschool sizes are too big for him. The photos in the toddler and standard KP's show the wrinkles (or bunching) that occurs (usually close to where the straps attach) when a baby is too small for the KP. (Yes, I know he's a toddler but I'm going to call him a baby as long as I can!)
Spencer in Infant KP
Spencer in Standard KP
Spencer in Toddler KP
Spencer in Preschool KP
Our second model is Lincoln. He's 24 months old. He is 31 inches tall and 29 pounds. The infant Kinderpack is too small for him. Both standard and toddler sizes are appropriate for him.
Lincoln in Infant KP
Lincoln in Standard KP
Lincoln in Toddler KP
Lincoln in Preschool KP
Our third and final model is Celia. Celia is 3.5 years old. She is 37 inches tall and 33 lbs. I usually wear Celia in a toddler size (but sometimes a standard). She is only knee-to-knee in the preschool size but is well-supported in both the standard and toddler sizes. I would be comfortable wearing her in standard, toddler or preschool sizes.
Celia in Infant KP
Celia in Standard KP
Celia in Toddler KP
Celia in Preschool KP
As you can see, there's a lot of overlap in sizes for the Kinderpack. While each child has a size that fits them best, I could easily wear all three children in a standard size.
And since we're talking about Kinderpacks, I'll make a little announcement. We now have both infant and standard sizes in both libraries! The pretty kitties infant size KP in these photos was recently purchased and will now be in the Sugar Grove library. It has perfect fit adjusters so it will be great for all you petite caregivers as well. This adorable cupcakes KP is a standard size KP (with PFA's as well) and will be in the Rockford library.
We hope to eventually add the toddler and preschool sized KP's. Our leaders have toddler and preschool sized Kinderpacks and are happy to bring them too meetings when requested.