Check what a sale price actually comes to before you get to the till. Pick Percent off if the sign says something like “30% off” and you want the price you pay, or Find % off if you can see both the original and the sale price and want to know how good the deal really is. Tap a preset to fill in a common discount, or type your own. The result shows what you save and what you pay, so you can compare two offers quickly.
Original price–
Discount–
You save–
You pay–
Prices here are before sales tax. Tax is normally worked out on the discounted price, so add your local rate to the "You pay" figure.
How it works: The sale price is original × (1 − discount ÷ 100), and the saving is original × discount ÷ 100. Going the other way, percent off = (original − sale) ÷ original × 100. Two stacked coupons multiply rather than add: 20% off then an extra 10% off is 28% off in total, not 30%.