Net Pay After Tax

How the calculations work

Version 0.2 is an annualized standard-employee estimator. It is designed to answer “roughly what do I take home?” rather than reproduce every employer payroll edge case.

Canada 2026

The engine uses 2026 federal and provincial/territorial progressive tax brackets, the standard basic personal amount, the Canada employment amount, employee CPP/CPP2 and EI. British Columbia includes its 2026 tax reduction. Ontario includes provincial surtax, the Ontario tax reduction and Ontario Health Premium.

Quebec uses a separate branch: 2026 Quebec income-tax bands and basic personal amount, QPP, Quebec EI, QPIP and the federal 16.5% Quebec abatement.

United Kingdom 2026/27

The engine uses the £12,570 Personal Allowance with the £1-for-£2 reduction above £100,000, England/Wales/Northern Ireland bands or Scottish bands, plus employee Class 1 National Insurance.

United States 2026

The U.S. foundation uses the IRS 2026 standard deduction and federal rate schedules for Single, Married Filing Jointly and Head of Household. Employee payroll tax uses 6.2% Social Security up to the 2026 wage base of $184,500, 1.45% Medicare, and the 0.9% Additional Medicare Tax above the applicable threshold.

Texas and Florida have no individual state income tax. California uses the published 2026 FTB tax schedules and standard deductions plus the 2026 employee SDI rate of 1.3%. New York uses the official 2026 NYS-50-T-NYS annualized withholding schedule with zero New York exemptions for Single and Married status. NYC and Yonkers local taxes are not included.

50-state U.S. coverage in v0.6

All 50 states now have a state page. For states newly added in v0.6, the state layer is a standard 2026 income-tax liability estimate using published state rates, brackets, standard deductions, basic exemptions or basic taxpayer credits. Federal tax and FICA continue to use the 2026 federal engine.

Important scope: this is not a full employer-withholding reproduction for every state. Local/city/county income taxes are excluded, and most state paid-leave, disability or similar employee payroll premiums are excluded except California SDI. Head of Household uses the state's single-filer schedule where a separate state HOH schedule has not been encoded; the federal Head of Household calculation remains separate. New York Head of Household is blocked instead of estimated.

Not yet modelled

Individual TD1/TP-1015 claims beyond the standard basic amounts, pensions, student loans, RRSP deductions, taxable benefits, union dues, multiple jobs, tax codes other than the standard UK allowance, payroll-period rounding and many specialized credits are not included.

Primary references