Accounting firms
Put a Canadian income-tax or sales-tax estimate on a service page. The visitor’s numbers stay in the browser.
Who uses these tax calculators
Tax preparers
Show the year in the rate file, then point the client at the official return for anything the form does not ask.
Payroll providers
Pro estimates CPP, EI, and provincial withholding on a regular pay. It does not file a remittance.
Financial advisors
FHSA, RRSP, and take-home pay sit beside the rate file, so a new year does not require a rewritten page.
HR sites
A salary calculator lets an employee see a paycheque estimate without sending the gross wage to the server.
Writers and publishers
Embed one calculator in an article. The shortcode and the block use the same engine.
Agencies
Agency covers more sites and can hide the vendor name on a client install.