Second Job Tax Calculator Australia

How a second job is taxed in Australia

Australia does not have a separate tax scale for second jobs. When you lodge your tax return, every taxable dollar you earned is added together: your main salary, your second job, overtime, bonuses, interest and any other assessable income. The progressive rates are then applied to the total. The second job is not taxed “from zero” again; it sits on top of your main income and is effectively taxed at your marginal rate.

Extra tax from a second job = tax on (main income + second income) − tax on main income alone.

That formula explains why a second job can feel heavily taxed. If your main salary already uses up the 15% and 30% brackets, most of the second job income falls into the 30% or 37% bracket, plus the 2% Medicare levy. The calculator shows the extra tax and the effective rate on the second job, which is usually higher than the rate you see on your main payslip.

The tax-free threshold: claim it once

The tax-free threshold exempts the first $18,200 of taxable income. You claim it through your Tax File Number declaration, and you should claim it on one job only. Claiming it on your main job is usually right. If you claim it on a second job as well, both employers withhold as if their job is your only income. The result is too little tax withheld across the year, and a bill when you lodge.

If your total income is below $18,200, claiming the threshold on your only job is obviously correct. If you have two low-paid jobs, the answer can be less obvious; the ATO’s withholding variation process can help you set a rate that matches your actual combined income. Thetax withheld calculator shows the difference between the threshold and no-threshold scales for a weekly or fortnightly pay.

Why second job withholding often falls short

Most second employers withhold tax using the no-threshold scale. That scale applies the lower tax brackets to the second job as if it were a standalone income, which usually withholds less than the marginal rate you actually pay on top of your main salary. For example, a $20,000 second job on top of an $85,000 main salary attracts roughly 32% in extra income tax and Medicare, but the no-threshold schedule withholds at an average rate closer to 18%. The difference is the shortfall shown in the calculator.

This is not double taxation. The withholding is a prepayment, and your tax return reconciles it. If you want to avoid a bill, you can ask your second employer to withhold more, apply to the ATO for a PAYG withholding variation, or move part of the extra income into savings each pay. Keeping receipts for work-related expenses and claiming deductions also reduces the final liability.

A HELP debt makes the shortfall larger. The compulsory repayment is based on your total repayment income, so the second job can push you into a higher band even though neither employer withholds the exact extra amount. Switch on HELP in the calculator to see the effect.

Medicare, super and other considerations

The Medicare levy is 2% of taxable income for most residents, with a low-income reduction and different thresholds for families. It is calculated on your combined income, not separately for each job. Employer super is paid on top of your gross pay and does not reduce the income tax on either job, although the second employer must also pay the 12% guarantee on superable earnings up to the maximum contribution base.

If you are a contractor rather than an employee, the second job may not have PAYG withheld at all. In that case you may need to quote an Australian Business Number, charge GST once turnover reaches the threshold, and set aside tax for your return. The same combined-income principle applies, but the cash-flow risk is larger because nothing is withheld during the year.

Second job tax examples for 2026–27

Each row assumes a resident taxpayer claiming the tax-free threshold on the main job, the 2% Medicare levy, no HELP, no deductions and no other income. The “gap” is the extra tax minus the no-threshold PAYG withheld from the second job. A positive gap is an estimated amount owing.

Withholding amounts are annualised from the ATO’s 2026–27 no-threshold weekly schedule and assume 52 weekly pays. Actual payroll withholding can vary with pay frequency, rounding, allowances and declarations.

Planning around a second job

Treat the extra tax, not the gross second-job pay, as the real value of the work. If the second job pays $20,000 but the extra tax is $6,400, the after-tax contribution is about $13,600 before work-related costs. Factor in travel, equipment, union fees and the time involved.

To check your overall position, put your combined income into the salary calculator for a full take-home breakdown, or use thetax return calculator to compare your total withholding with your estimated liability. If you also receive a one-off payment, the bonus tax calculator shows how it interacts with your marginal rate.