I’ve recently started a cake making business and would class my self as a novice baker as I’ve only been making cakes for about a year. 

I've been asked to make a 3 tier wedding cake and literally have no idea what to charge for it. I know that it’s probably going to cost around £100-£120 to make (depending on flavours the client chooses)

I ask as i’ve never made a 3 tier before, only a 2. I know a 2 tier I recently made tuck me 4 evenings and 1 morning. (Not very helpful I know, sorry) but I don’t want to charge the client based on how long it takes me as I get that I will be slower than an experienced baker.

the cake the client has asked for is semi naked, with drips, 24k gold leaf and fresh flowers.

I read that a cake maker should charge £10-£15 per hour so how long should this take on average and is this figure correct?

any help would be much appreciated.

What are others in your area charging?   Here in the US we charge by the # of servings starting around $4 to $6 per serving.  So if the total of the 3 tiers serves say 84 then you would charge around $350-$550 (sorry - don't know how that translates into your currency).  Hope that helps some.

Most new decorators do charge per serving.  With time, you will become faster and may decide to change the way you charge.