One of the most significant financial decisions an Australian business owner makes is choosing their business structure. Operating as a sole trader is simpler and cheaper to set up, but once your profit reaches a certain level, a company structure can result in meaningfully less tax.

The problem is that most business owners have no easy way to see the numbers side by side for their own situation. This calculator fixes that. Enter your expected annual profit and see exactly what you would pay in tax under each structure.

What This Tool Does

The Sole Trader vs Company Tax Calculator takes your expected annual business profit and calculates the tax payable under two scenarios — operating as a sole trader and operating as a proprietary limited company (Pty Ltd).

For the sole trader calculation, it applies the current Australian resident individual income tax brackets, the Medicare levy at 2%, and the Low Income Tax Offset (LITO) where applicable. The result shows income tax, Medicare levy, LITO reduction, total tax payable, effective tax rate, and your estimated take-home amount after tax.

For the company calculation, it applies the flat 25% company tax rate that applies to base rate entities — companies with an aggregated turnover of less than $50 million where 80% or less of their income is passive income. The result shows company tax payable, the after-tax profit retained in the company, and the effective tax rate at the company level.

The tool then identifies which structure results in less tax at that profit level and explains why, in plain language, without requiring any accounting knowledge.

How the Tax Comparison Works

The core difference between the two structures comes down to how income is taxed. As a sole trader, all business profit is treated as your personal income and taxed at progressive marginal rates. In Australia, the top marginal rate of 45% applies to income above $180,000, and rates step up progressively from 19% on income above $18,200.

A company is a separate legal entity and pays tax at a flat rate on its profits — currently 25% for small base rate entities. This flat rate does not increase with profit level, which is why the company structure becomes increasingly tax-efficient as profit grows.

At lower profit levels — typically below $45,000 to $80,000 depending on the specific amount — the sole trader structure is often more tax-efficient. This is because progressive rates at lower income levels, combined with the Low Income Tax Offset and the tax-free threshold, can result in a lower effective rate than the flat 25% company rate.

As profit increases above that range, the company rate becomes progressively more attractive. At $120,000 profit, for example, a sole trader pays a marginal rate of 32.5% on the bulk of their income plus Medicare levy, while a company pays a flat 25% on the entire amount. The gap widens further above $180,000 where the top marginal rate of 45% applies.

The Important Nuance — Company Tax Is Not the End of the Story

The calculator compares tax at the entity level — what the sole trader pays personally versus what the company pays on its profit. But the company comparison requires an important qualification that the tool explicitly flags.

When profit is retained in a company at 25% tax, it has not yet been fully taxed. When that profit is eventually paid out to you as a dividend, you pay personal income tax on it — though you receive a franking credit for the tax already paid by the company. The total tax paid across both levels (company and personal) is broadly similar to what a sole trader would pay at the same income level once you account for the full distribution.

The real tax advantage of a company structure is deferral, not elimination. If you can leave profits in the company — to fund growth, build a buffer, or invest — rather than paying them all out as personal income immediately, you are paying 25% now and deferring the personal tax on the remainder until you choose to distribute it. For a business owner in the 45% marginal bracket, that deferral is genuinely valuable.

This is why the company structure is particularly powerful at higher income levels, and why the calculator is most useful as a starting point for a conversation with your accountant rather than a definitive answer.

When to Consider Switching Structures

The calculator is useful at any stage, but it is particularly relevant in three situations. The first is when you are starting a business and choosing your initial structure — understanding the tax implications from day one can save significant money over time.

The second is when your business profit is growing and you are approaching the threshold where a company structure becomes more efficient. Most accountants suggest reviewing your structure when annual profit consistently exceeds $80,000 to $100,000, though the exact crossover point depends on individual circumstances including other income sources, deductions, and plans for distributing profits.

The third is when you are planning for growth and want to retain profits in the business to fund it. If you intend to leave a significant portion of profits in the business rather than drawing everything as personal income, the company structure offers a lower tax rate on retained earnings that can compound meaningfully over time.

Changing from a sole trader to a company involves upfront costs — ASIC registration, potential stamp duty on asset transfers, and accounting fees — so it is worth modelling the numbers carefully before making the switch.

Disclaimer

This calculator is a general educational tool only and does not constitute financial, tax, or legal advice. The calculations are based on Australian resident individual income tax rates, the Medicare levy, the Low Income Tax Offset, and the small business company tax rate as they apply under current Australian tax law. They assume no other income sources, no additional deductions beyond the profit figure entered, and a neutral tax position.

Tax law in Australia is complex and individual circumstances vary significantly. The comparison shown does not account for personal drawings, salary packaging, trust structures, superannuation contributions, capital gains, Division 7A loan issues, or the personal tax implications of distributing company profits as dividends. The rates and thresholds used in this calculator reflect current legislation and are subject to change.

Before making any decision about your business structure, speak with a qualified accountant or tax adviser who can assess your full financial situation. The Australian Taxation Office website at ato.gov.au provides authoritative information on business structures and tax obligations.