Float bags for Sonoma 13.5

I’m a beginner and I just purchased a Perception Sonoma 13.5. The kayak has a stern hatch but the bow just has the center foam pillar - no hatch. I know I need split flotation bags for the bow, but I don’t know what size. The websites I’ve seen say to measure and get the size that’s slightly bigger. I’m just not sure how to measure and I don’t want to end up with bags that are too small.

Can anyone give me some advice? I want to be safe on the water!

Length and width
Float bags are typically sized by length and width at the widest point.

Measure from the inside of the bow of your kayak to the front (towards the bow, away from your feet) of your foot pegs. That’s the length.

Then measure the distance from the center pillar to the side of the boat at the foot pegs. That’s the width.

That helps, but…
Okay, that helps a lot with the width part. As for the length part, I’m still not quite clear. I tried measuring that way, and now the tape measure is stuck 8-). When I manage to free it, can you give me an idea of how far forward to measure? I pushed it all the way forward to the tip - should it just go to the end of the pillar (assuming I can tell where it ends)?

Thanks very much for the quick reply!