A $120 item at 30% off costs $84 before tax, a saving of $36. In Ontario, 13% HST adds $10.92, so the final price is $94.92. Take a further 10% off the sale price and the final total falls to $85.43.
How a discount is calculated
Multiply the original price by the discount percentage to get the saving, then subtract it. There is a shortcut: multiply the price by one minus the discount. For 30% off, that means 0.70. The calculator shows both the sale price and the amount saved.
Extra discounts
Stores sometimes take a further percentage off a price that is already reduced. That is not the same as adding the two percentages. Thirty percent off, then 10% off, totals 37% off and not 40%. The extra field applies the second discount to the sale price.
Work it through with the example. Take 30% off $120 and the price is $84. A further 10% off $84 saves $8.40, so the price becomes $75.60. Compared with $120, you saved $44.40, which is 37% of the original price. Tax at 13% on $75.60 is $9.83, so the total is $85.43. Applying 40% to $120 would give $72 instead, and that is the common mistake of adding percentages.
Sales tax comes after
In Canada the discount comes off first, so tax is charged on the lower price. Pick your province to see the tax on the sale price. HST provinces charge one combined tax, and others charge GST plus a provincial tax where it applies.
To find a discount from two prices, subtract the sale price from the original and divide by the original. A jacket marked down from $150 to $105 is $45 lower, and $45 divided by $150 is 30%. Reverse the steps to find the original price from a sale price: divide $84 by 0.70 and you get $120. Stores that advertise up to 50% off often apply that figure to only a few items.
Coupons and rebates
A store coupon is usually a discount and lowers the taxable price. A manufacturer coupon may not, and then tax can be based on the higher price. Mail-in rebates arrive after you pay, so they leave the tax alone. Read the terms at the till.
Is the sale real?
Compare the sale price with what other stores charge and what the item cost last month. A big discount off an inflated price is no bargain. Use the calculator to see the real price after tax and decide if it fits your budget.
Big purchases and unit prices
On expensive items the province matters more. A $2,000 purchase in Ontario adds $260 in HST, while in Alberta it adds $100. Compare the total, delivery and warranty included, and not the discount alone. Bigger packs are not always cheaper either. Divide the sale price by the number of units and compare with other sizes, because 30% off a large pack can still cost more per item than a smaller pack at a regular price.
Price matching and returns
Many stores match a lower competitor price, and some refund the difference if an item goes on sale soon after you bought it. Keep your receipt and ask before you pay. Check that any refund includes the tax you paid, since it should.
Shopping in Toronto and Ontario
Ontario charges 13% HST on most goods, but some items, such as basic groceries and children’s clothing, are exempt or zero-rated. Choose Ontario in the province list to see the tax on your sale price. Holiday sales at Toronto stores often end within days, so check the number before you buy.
Where to go next
Check percentages in the percentage calculator. Add or remove tax with the GST and HST calculator. For provinces with a separate tax, use the PST and QST calculator.
Frequently asked questions
How do I calculate a discount?
Multiply the price by one minus the discount percentage.
Is tax charged before or after the discount?
After. Tax is charged on the discounted price.
What is 30% off $120?
$84, which saves you $36.
Are two discounts added together?
No. The second applies to the reduced price, so 30% then 10% is 37% off.
Does a coupon lower the tax?
A store coupon usually does. A manufacturer coupon may not.
How do I find the final price?
Add your province's sales tax to the sale price.
Sources and updates
Last reviewed: . Full disclaimer. How we build calculators. Editorial policy.
Estimate only. This calculator gives general information for planning. It is not tax, legal or financial advice, and it is not affiliated with the City of Toronto, MPAC or the Canada Revenue Agency. Results depend on the numbers you enter and may differ from official amounts. Check official sources or a qualified professional before you decide.