Calculate FX differences

Hi all,

I am new to this forum. I have a question regarding the calculation of FX differences. Let's say I have an amount of 1000 USD and I do like to calculate this into EUR for two different FX rates, say 0.7 and 0.8, how would I do this in Excel?

Clarification: I mean to create a cell that shows the impact of the F/X effect i.e. the difference between the two conversions.

Thanks in advance.