Confused about Torso vs Slot measurements

[autumnlily]

I took my kiddos torso heights by having them sit cross-legged on the floor and measuring to their shoulder. The twins were both shy of 12" (with cloth diapers on) and my oldest DD was about 14" (she was not fully cooperating and this may be a little shorter than actual).

I'm confused because, when the twins are in their MA rearfacing the straps are at or a tiny bit ABOVE their shoulders. It's my understanding that the bottom slot is 10". What am I doing wrong or is this normal?

[Shaunam]

Measuring torso height isn't an exact science. Kids always seem to grow or shrink when they are actually put in the vehicle. My DS sits down lower rf'ing than he does ff'ing and when I recline his seat a bit ff'ing he seems to grow a bit. When he was rf'ing, putting him upright made him grow and reclining him made him shrink. Yeah, it's weird. The ultimate test is just putting them in the installed seat to see how they fit. Which is why babies'r'us is awesome for having a test bench...you can get a better idea of how your kid will actually fit in the seat.