CountIF - remove duplicates

[Zoeb]

I have a spreadsheet that tells me customers that have been referred to my business eg. Customers referred via route A, B, C, D. Aswell as the nunber of referrals via each route I'd like to count the number of customers. Eg, I may have 20 referrals via route A but 1 customer has been referred 8 times. Another may have been referred via route A 12 times. So amount of referrals would be 20 but a mount of actual customers would be 2.

So I would need to remove duplicates after the whatif function is there a formula for this?

 

[DanteAmor]

Hi and welcome to MrExcel.

You could put a sample of your data, to see how they are on your sheet.
If they are confidential data, replace them with generic data.
To put cell ranges use the XL2BB tool, see my signature.