How To Calculate Your Coupon Savings
To calculate your coupons savings percentage you would take the total amount that you would have paid (reg. prices without coupons and sales) and subtract the amount that you did pay (after sales and coupons). This will give you the amount you saved.
You then take the amount that you saved and divide that by the regular amount that you would have paid. This will give you your savings percentage.
Savings Total ÷ Regular Total = % Saved
Also see The Scanning Code Of Practice