Formula to calculate new cell value based on a range of possible increases

Originally Posted by Sambo kid

you have under 20 and over 20 etc, what about exactly 20 and exactly 100 etc.?

Here is a fix:

If equal to or under $20, then add $2
If over $20, but equal to or under $100, then add $5
If over $100, but equal to or under $200, then add $10
If over $200, but equal to or under $300, then add $15
If over $300, then add $20