As I say in the Consultant’s Guide 4: How much to charge, what you charge is more than just numbers.
Take into account what you can charge as well as what you need to charge. Do a little market research – find out what others are charging, what the client is currently paying. What you feel comfortable charging.
Remember what I call the Barbra Streisand pricing formula (She’s Barbra, she can charge whatever she likes). You can update that to any celebrity or super model you know, the idea is that your brand affects your charge-out rate (expensive or bottom of the line).
Remember also what Alan Weiss says: no client ever stands in front of a group and says “This is the cheapest consultant we could find, pay attention to them“. But they will say the reverse: “This is the most expensive consultant I’ve ever encountered: pay attention, I don’t want to waste my money“!
Get a sample of Consultant’s Guide 4: How much to charge here.