Help! Making excel choose the right calcualtion

[Markmake12]

Hello, this is my first post!
I need to make excel recognise data in one coloum to then decide which sum from a hidden colum to use to multiply by to give the correct total.
I would like to enter a reading in cell b1, this will be a number between 12 to 22. I would then like it to decide which sum to use to work out the total to be entered on that cell. Each number from 12 to 22 has a different value. (Cost to multiply it by)
The layout is
Cell a1 has the weight,
Cell b1 has the moisture
Cell c1 would then have the cost to dry to - this is where I need a formula to see which number is in b1 so it decides to us the data for that entered moisture number to then multiply it by the weight entered in a1 to give me a total based on each load by load.
Any suggestions really appreciated!

So if I enter 10000kg in a1 and 14.4 in b1 it knows that it needs to use the costing for 14 - 15. Then in cell c1 show me the calculated value.

Thank you mark

[mehmetcik]

Attach a sample workbook (not a picture or pasted copy). Make sure there is just enough data to demonstrate your need. Include a BEFORE sheet and an AFTER sheet in the workbook if needed to show the process you're trying to complete or automate. Make sure your desired results are shown, mock them up manually if necessary.

Remember to desensitize the data.

Click on GO ADVANCED and then scroll down to Manage Attachments to open the upload window.