Using IF and ISBLANK

Copper Contributor

I have a spreadsheet used to track courier costs and recharge our clients. I need to add a formula that adds either £20 to courier costs under £100 or 20% if over £100. This is fine and I can create no problem. Where I am struggling is to only return a value when the cell with the courier cost is filled.


=IF(ISBLANK(K3)<100,20,K3*0.2) seemed to work, but actually only adds 20% regardless. Where am i going wrong with this?


1 Reply
best response confirmed by sparkle99 (Copper Contributor)
=IF(ISBLANK(K3), "", IF(K3<100, K3+20, K3*1.2))