A little excell question

[Taff]

I keep a spreadsheet of everything that I do to the tiger because I like to know how long things last - brake pads, tyres etc and how much oil I'm adding to the engine.

In column A I have mileage, column B the amount of oil added in ml.

what I'm trying to get excell to do is tell me how much oil is added per 1000 miles so that I can pick up any change (increase) early on, any ideas?

[DefTrap]

So in cell c2 you want =b2/(a2-a1)
That will give you the oil per mile for the first entry.
Then just copy it down the c column.

[iansoady]

You might want to make it =1000*b2/(a2-a1) to give you oil per 1,000 miles as oil / mile is likely to be tiny.

[Taff]

thats great, thanks

I've modified that slightly to smooth out the graph and currently have =sum(B2:B6)/A6-A2 which gives me the total oil added / mileage range which is the sort of rate that I'm looking for.