Discount Calculator

Sequentially, not additively: 30% off then an extra 20% off means the 20% applies to the already-reduced price — a $100 item goes to $70, then to $56, which is 44% off total, not 50%. Stores phrase promotions this way precisely because 'extra 20% off' sounds like it adds. The calculator shows the true combined percentage whenever you enter a second discount.

Reverse mode: enter the original and sale prices, and the discount percent comes back — (original − sale) ÷ original × 100. Useful for judging whether a 'deal' is real: $89.99 marked from $119.99 is 25% off, decent; marked from $99.99 it's 10%, marketing.

After, in virtually all US states — you pay tax on what you actually paid, so a discount also shrinks the tax. Coupons can differ (some states tax the pre-coupon price for manufacturer coupons since the retailer is reimbursed), but for store discounts and clearance, discounted price × tax rate is the rule. The sales tax calculator finishes that math.

10% is one decimal shift ($43.00 → $4.30); build the rest from it: 20% is double that, 5% is half, 15% is 10% + 5%. 25% is quarter-off (divide by 4), and for 30–40% it's often faster to compute what you pay: 30% off means pay 70%, so shift the decimal and multiply by 7.