# Ontario semi-monthly payroll deductions 2026

Works out the federal and Ontario income tax, CPP, CPP2 and EI on a semi-monthly pay, the net pay and what the employer pays on top, by CRA's T4127 formulas. This page describes the calculator and does not compute. The calculator is a web page with a form.

## An estimate

An estimate. The employer remains liable to CRA for the amounts it deducts and remits. Check a result with CRA's Payroll Deductions Online Calculator (PDOC) before relying on it.


## What you enter

A pay frequency (weekly, biweekly, semi-monthly or monthly), the gross pay for one pay period, the federal and Ontario claim amounts, the pay date and, optionally, what was deducted and earned on earlier pays this calendar year.

Leave a claim empty for the basic personal amount (claim code 1). Type 0 for claim code 0, or the total from the employee's TD1 and TD1ON.

A pay date left empty is today. Money may be written as 1234.5, 1,234.50 or $1,234.50.


## How this is worked out

CPP is the employee's base and first additional contribution on the pay above the basic exemption for one pay period, up to the year's maximum. CPP2 is the second additional contribution on pensionable earnings above the year's maximum pensionable earnings, up to the additional maximum. EI is the employee's premium on insurable earnings, up to the year's maximum.

For income tax, the pay is turned into an annual taxable income, A: the number of pay periods times the pay, less the CPP contributions that are deducted from income. The federal and Ontario tax on A is worked out with the brackets and credits of T4127; the Ontario surtax and Health Premium are added and the Ontario tax reduction is taken off. Each year's tax is divided by the number of pay periods and rounded to the cent.

The employer pays the same CPP and CPP2 as the employee, and EI at the multiple of the employee's premium that T4127 sets.

Pensionable and insurable earnings are taken to be the gross pay. Every factor the formulas used is listed with its value.


## The tables

Tables of CRA's T4127 Payroll Deductions Formulas, 123rd edition, for pay dates from 2026-07-01 to 2026-12-31.

- [T4127 Payroll Deductions Formulas, 123rd edition](https://www.canada.ca/content/dam/cra-arc/formspubs/pub/t4127-jul/t4127-jul-26e.pdf)

## Check it yourself

1. Open CRA's Payroll Deductions Online Calculator (PDOC), accept the terms and choose Salary.

2. Enter Ontario, the same pay frequency, the same date paid and the same gross salary, with nothing else in the income fields.

3. Choose claim code 1 for the basic personal amounts, or enter the same claim amounts. Enter the same year-to-date CPP, CPP2, EI and pensionable earnings; leave a zero field blank, as PDOC refuses 0.

4. PDOC's federal tax, provincial tax, CPP, CPP2 and EI should match this page to the cent. The pays this calculator was compared with are listed in the payroll-ca project.

- [CRA's Payroll Deductions Online Calculator (PDOC)](https://www.canada.ca/en/revenue-agency/services/e-services/digital-services-businesses/payroll-deductions-online-calculator.html)
- [The pays compared with PDOC, and how (payroll-ca)](https://github.com/wenmar-pro/payroll-ca#check-a-result-yourself)

## A worked example

The page opens with this example: a semi-monthly pay of $2,400.00, with the claims left to the basic amounts and the pay date 2026-07-01.

Federal claim: $16,452.00, the basic personal amount of the tables (claim code 1). Ontario claim: $12,989.00, the basic personal amount of the tables (claim code 1).

Deductions from one semi-monthly pay:

| Pay | Amount |
| --- | --- |
| Gross pay | $2,400.00 |
| Federal income tax | $207.02 |
| Ontario income tax | $115.51 |
| CPP (base and first additional) | $134.12 |
| CPP2 (second additional) | $0.00 |
| EI | $39.12 |
| Total deductions | $495.77 |
| Net pay | $1,904.23 |


## The factors of the worked example

The T4127 factors used:

| Factor | Value | What it is |
| --- | --- | --- |
| P | 24 | Pay periods in the year. |
| PM | 12 | Months of the year in which the employee contributes to CPP. |
| C | 134.12 | The employee's CPP contribution on this pay, base and first additional. |
| C2 | 0 | The employee's second additional CPP contribution (CPP2) on this pay. |
| EI | 39.12 | The employee's EI premium on this pay. |
| F5 | 22.54 | The part of this pay's CPP that is deducted from income before tax: the first additional contribution and CPP2. |
| F5A | 22.54 | F5 for the regular pay; with no bonus it is F5 whenever there are pensionable earnings. |
| A | 57059.04 | Annual taxable income: pay periods times this pay, less F5A. |
| R | 0.14 | The federal tax rate for the bracket A falls in. |
| K | 0 | The federal constant for the bracket A falls in. |
| K1 | 2303.28 | The federal credit for the federal claim amount, at the lowest federal rate. |
| K2 | 506.35 | The federal credit for a year of base CPP contributions and EI premiums at this pay. |
| K4 | 210.14 | The federal credit for the Canada employment amount. |
| T3 | 4968.5 | Annual basic federal tax: R times A, less K and the federal credits, not below zero. |
| T1 | 4968.5 | Annual federal tax; with no labour-sponsored funds credit it is T3. |
| V | 0.0915 | The Ontario tax rate for the bracket A falls in. |
| KP | 2210 | The Ontario constant for the bracket A falls in. |
| K1P | 655.94 | The Ontario credit for the Ontario claim amount, at the lowest Ontario rate. |
| K2P | 182.65 | The Ontario credit for a year of base CPP contributions and EI premiums at this pay. |
| T4 | 2172.31 | Annual basic Ontario tax: V times A, less KP and the Ontario credits, not below zero. |
| V1 | 0 | The Ontario surtax on T4. |
| V2 | 600 | The Ontario Health Premium on A. |
| S | 0 | The Ontario tax reduction, which lowers or removes Ontario tax on lower incomes. |
| T2 | 2772.31 | Annual Ontario tax: T4 plus V1 and V2, less S, not below zero. |
| L | 0 | Additional tax per pay asked for on a TD1; none on this page. |
| T | 322.53 | Income tax deducted from this pay: federal and Ontario tax for the year, each divided by P and rounded to the cent, plus L. |


## What this covers

Ontario only, by T4127 Option 1, the regular method, for one regular pay. A bonus, retroactive pay or commission is worked out another way and is not covered.

Not taken into account: registered pension plan and RRSP deductions, union dues and other amounts a TD1 lets an employee deduct, additional tax asked for on a TD1, a CPP or EI exemption, and an employee who turns 18 or 70 this year.

An employee whose net income for the year will be high may be able to claim less than the basic federal amount: type the amount from their TD1.

This is arithmetic, not accounting or tax advice.


## Use it

The calculator as a web page:

- [Ontario semi-monthly payroll deductions 2026](https://open.wenmarpro.com/tools/payroll-deductions/ontario/semi-monthly)