Anyone check starter gravity after completion?

[gavinr]

Just checked my decanted wort from a completed (24 hrs @74F on a stir plate) and refrigerated (24 hr) starter.
Gravity was 1.018 - 50% attenuation. Final attenuation (Wyeast 3726 Farmhouse, 74-79%) should have been 1.008-1.009.
Anyone know of a way to calculate growth rate based on apparent attenuation?
I'm not too concerned about this one, as it is a 2-stage starter to build up a yeast pack that was 4 months old.

 

[gavinr]

Correction: Rookie mistake!!
I forgot I was reading fermented wort when converting refractometer reading to gravity. Actual gravity was 1.009, which was as expected.