How to use the Paycheck Calculator
- Enter gross salary and select your pay frequency.
- Add pre-tax deductions such as pension, health premiums or salary sacrifice.
- Enter your income tax and social-contribution rates.
- Read net pay per period and the annual total side by side.
How the calculation works
Order of operations decides the answer. Pre-tax deductions come off gross first, reducing the base for income tax and often for social contributions too. Income tax and payroll levies are then applied to that reduced figure, and only afterwards are post-tax deductions such as loan repayments or union dues subtracted.
Pay frequency introduces arithmetic traps. Fortnightly pay produces 26 cheques a year, not 24, so two months each year contain three payments — budgeting on 'twice a month' understates annual income and overstates the monthly figure. Semi-monthly pay gives 24 periods of uneven day counts, which matters for hourly staff but not for salaried employees.
Net = (gross − pre-tax deductions) × (1 − tax rate − contribution rate) − post-tax deductionsSource: Standard payroll sequencing: pre-tax deductions, statutory withholding, then post-tax deductions.
Worked example
Salary 58,000 paid fortnightly, 5% pension, 22% income tax, 8% social contributions.
- Gross per period = 58,000 / 26 = 2,230.77.
- Pension = 111.54, leaving 2,119.23 taxable.
- Tax and contributions = 30% × 2,119.23 = 635.77.
- Net = 2,119.23 − 635.77 = 1,483.46.
About 1,483 per fortnight, or 38,570 a year net against 58,000 gross.
Frequently asked questions
Why is my first paycheck smaller?+
Partial pay periods, start-date proration and one-off onboarding deductions commonly shrink the first payment.
Do pension contributions reduce tax?+
Pre-tax or salary-sacrifice contributions reduce taxable income, so yes. Post-tax contributions with later relief work differently.
How many pay periods are in a year?+
52 weekly, 26 fortnightly, 24 semi-monthly and 12 monthly. Fortnightly and semi-monthly are not the same thing.
Why does overtime seem taxed harder?+
Withholding often annualises a large period, temporarily assuming you always earn that much. It usually evens out at year end.
Last reviewed August 31, 2026. We review this page whenever the underlying formula, tax year, published rate or standard changes.