The calculation is correct:

1.0238 = 630.00 = Amt + Tax
1 = 630/1.0238 = 615.35 = Amt
630 - 615.35 = 14.65 = Tax

If you really want to get $15.00 tax from $630.00 use 2.43902 as your tax rate

This is 615 * .0243902 = 15.00


Edited by Michael Mulrooney (04/27/10 07:09 AM)