In my research, I've found 2 ways to calculate this.
Thanks!
CSAT (%) = (total responses given / total possible response scores) * 100
CSAT (%) = (# of very dissatisfied * 1) + (# of dissatisfied * 0.75) + (# of neutral * 0.5) + (# of satisfied * 0.75) + (# of very satisfied * 1) / (total responses)