If you want for 1000 = 50 and 2000 = 100 then

=A1*.05

this will return 37.5 for a value of 750

if you only want it to increase when a value increases by 1000 try

=INT(A1/1000)*50

HTH
Peter

"Confused" wrote:

What function do you use to get the value of one cell to be 50 for every 1000
value of another cell?