MapleWage

How We Calculate

This page is the full account of how every number on this site is produced. If you want to check our work, everything you need is here.

Sources

Rates last verified 9 August 2026.

What we calculate

Each figure assumes a single employee whose only income is employment income, claiming the federal and provincial basic personal amount and the Canada employment amount, with no other credits, dependants or deductions unless you enter an RRSP contribution. Steps, in order:

  1. Contributions on gross pay. CPP at 5.95% on earnings between $3,500 and $74,600 (QPP at 6.3% in Quebec); CPP2 at 4% between $74,600 and $85,000; EI at 1.63% to $68,900 (1.3% in Quebec); QPIP at 0.43% to $103,000 in Quebec.
  2. Taxable income. Gross less the enhanced portion of CPP or QPP, less all of CPP2, less any RRSP contribution. Quebec additionally applies its deduction for workers against provincial taxable income.
  3. Federal tax. The bracket walk, less non-refundable credits at 14% on the basic personal amount, the base portion of CPP or QPP, EI, QPIP where applicable, and the Canada employment amount. Quebec residents then receive the 16.5% abatement.
  4. Provincial or territorial tax. The jurisdiction’s bracket walk, less its own credits at its lowest rate, then any surtax, tax reduction or health premium that jurisdiction applies.
  5. Net pay. Gross less all tax and all contributions.

The CPP base and enhanced split

A CPP contribution is not a single thing for tax purposes. The base portion — 4.95% of the 5.95% total, capped at $3,519.45 — is a non-refundable tax credit. The enhanced portion above it, and the whole of CPP2, are deductions from taxable income. Collapsing the two produces the wrong tax for anyone earning above the basic exemption, and it is the most common error we see in Canadian calculators. Full explanation →

Annual rates, not payroll withholding rates

The CRA republishes its payroll formulas each 1 July. Where a province has changed its rules retroactively, the July edition carries prorated values for the remainder of the year, so that six months at the old rate plus six months at the prorated rate totals the correct annual amount. Those prorated values are not tax rates and we never publish them as such — every figure on this site uses the annual value that applies on your return. In 2026 this affects British Columbia, Newfoundland and Labrador, and Prince Edward Island. We document all three →

When official sources disagree

For 2026, the CRA’s summary page of provincial tax brackets shows Manitoba’s thresholds as indexed values. Both editions of the CRA’s own payroll formulas — the operational source employers actually use — show them unchanged at $47,000 and $100,000, and the July edition states explicitly that nothing changed for Manitoba. Manitoba paused indexation of its brackets and basic personal amount, which its 2026 budget confirms.

We publish the payroll-formula values, because the operational source is the one that reflects the legislation. We then verified the choice empirically: at a $50,000 Manitoba salary our provincial tax figure agrees with the CRA’s own calculator to within a rounding cent, which it would not if the indexed thresholds were correct. Where a summary source and an operational source conflict, we follow the operational source and record the discrepancy here.

Validation

Our engine is checked against the CRA’s Payroll Deductions Online Calculator across multiple jurisdictions. We test at salaries below the CPP and EI ceilings, where the CRA’s per-period withholding annualises exactly and an exact comparison is meaningful. Federal tax agrees to within a few cents; provincial tax agrees to within a rounding cent in every jurisdiction with no mid-year change.

For British Columbia and Newfoundland and Labrador, where rates changed mid-year, we verified that our annual figure equals the average of the CRA’s January and July results — which is precisely what proration is designed to produce. For British Columbia the two reconcile to one cent.

Beyond the source comparison, an automated test suite asserts that across every jurisdiction and the whole salary ladder: net pay never exceeds gross, net pay rises with every increase in gross (so a raise can never reduce take-home), marginal rates stay within range, and the band tables always reconcile to the totals we display.

Rounding

All rounding happens once, at the point a figure is displayed. Nothing is rounded mid-calculation. Displayed amounts are to the nearest dollar unless a cent-level figure is meaningful, such as a statutory maximum. Your actual pay stub may differ by small amounts because payroll systems calculate per pay period and truncate at intermediate steps.

What we do not model

Self-employment, commission income, multiple employers, taxable benefits, dependants, tuition, medical or donation credits, pension income splitting, union dues, provincial low-income benefits, and income-tested benefit clawbacks. Adding an unmodelled credit will lower your real tax relative to our figure.

Corrections and updates

Rates are re-verified at the 1 January indexation, after each provincial budget, on the annual EI rate announcement, and on the annual CPP maximum announcement. Our build fails if our stored rates and the published CRA figures disagree, so a silent source change cannot reach the site. Found an error? Email support@inventum.com.au and we will correct it and note the change here.