Where the numbers come from

One file for every number

Not a single amount is hard-coded inside a calculator. All three read from the same file, calc-data.js, which holds the tax year, the contribution rates, the income tax brackets for all ten provinces and the overtime rules. When the 2027 figures change, that one file is edited once and all three calculators change together. There are no stray copies quietly going stale.

Federal contributions (2026)

• CPP — 5.95% on what you earn between the $3,500 exemption and the $74,600 maximum.
• CPP2 — an additional 4% between $74,600 and $85,000.
• EI — 1.63% from the first dollar up to $68,900 of insurable earnings.

Source: Canada Revenue Agency (CRA), which publishes these rates every November for the following year.

Quebec, which goes its own way

• QPP — 6.3% instead of CPP.
• QPIP — 0.43% for parental insurance, which EI covers in the rest of the country.
• Reduced EI — 1.30%, precisely because QPIP takes on parental leave.
• Abatement — federal tax is reduced by 16.5%.

Source: Revenu Québec.

Federal and provincial tax

The federal brackets start at 14% on the first $58,523, with a basic personal amount of $16,452 and the Canada employment amount of $1,500, both applied as a credit at the lowest rate. Each province has its own brackets and its own basic amount; Ontario adds its surtax and health premium on top.

Provincial brackets and basic personal amounts are reviewed once a year against the tables published by the CRA and by each province.

Overtime

There is no national rule: the calculator applies each province's daily and weekly thresholds, plus the distinction almost nobody implements — in Alberta, Manitoba and Saskatchewan the law pays the greater of the daily and the weekly calculation, not the sum of both; and British Columbia is the only one that combines them and also pays double time after 12 hours in a day. The sources are each province's labour ministry.

What these calculators do NOT cover

This matters as much as everything above. The net pay calculation does not include:

• Credits for children, spouse or disability.
• RRSP contributions, company pension or union dues.
• Taxable employer benefits (insurance, vehicle, housing).
• Income from other sources, nor the self-employed case, which pays both halves of CPP.

And the overtime rules do not cover trade-specific exemptions (construction, trucking, agriculture, management, commission sales), written hours-averaging agreements, or the federally regulated sector specifically.

Why your pay stub may say something else

Your employer withholds based on what you earned in that pay period, and the system assumes you will earn the same all year. That is why a pay period with a lot of overtime looks punished, and why partway through the year, when you hit the CPP or EI maximum, your cheque suddenly goes up. The calculator reasons about the full year, so compare annual with annual, not a single pay period.

If you find an error

Write to etrinidad.dev@gmail.com with the province, the income and the figure you expected. A correction backed by concrete numbers gets fixed in the file, and stays fixed for everyone.