Everyday Math Calculators for Money and Shopping

This hub is for shoppers, employees and small business owners who need a quick answer to a money question. It covers everyday decisions like whether a sale is really a bargain, how a raise compares with inflation and what a product must sell for to leave a profit.

The discount calculator takes off the markdown and adds sales tax for your province. The percentage calculator handles change, share and difference. Owners can price goods with the profit margin calculator, and investors can compare two choices with the ROI calculator.

Sales tax is where people slip most often, since Ontario charges 13% HST and other provinces use different mixes. Our GST and HST calculator shows the tax on its own line.

Each page shows the working line by line, so you can copy the steps into a spreadsheet or check a quote from a supplier. That makes them handy for comparing two offers before you commit, or for explaining a price to a customer.

The maths here is plain arithmetic, and the sales tax rates come from the Canada Revenue Agency and provincial governments. We review the rates once a year and whenever a province changes them.

Everyday Math Calculators for Money and Shopping on this site

• Percentage Calculator Work out percentages, percentage change and add or subtract a percent.
• Profit Margin & Markup Calculator Work out profit margin and markup, or the price for a target margin.
• ROI & Payback Calculator Work out return on investment, yearly return and payback period.
• Discount & Sale Price Calculator Work out a sale price after a discount and the sales tax on it.

Every calculator lists its sources. Read how the calculators work and our editorial policy.