As suggested by Gord Dibben, using JE McGimpsey's variable rate
formula...

=SUMPRODUCT(--(A1{0,600,800,1000,1200}),A1-{0,600,800,1000,1200},{0.06,0
..02,0.02,0.05,0.15})

Hope this helps!

In article ,
"Dave Smith" wrote:

Thanks Vasant.

Now what if the rate calculation gets more complicated? Is there some way
to use a lookup table? For example:

0-600 costs .06 per kwH
601-800 costs .08 per kwH over 600
801-1000 costs .10 per kwH over 800
1001-1200 costs .15 per kwH over 1000
1200 costs .30 per kwH over 1200