Free Australian break-even calculator. Enter your total fixed costs, selling price per unit, and variable cost per unit to instantly find your break-even units and break-even revenue using the contribution-margin formula. Includes a target-profit mode that shows the units and sales needed to hit a profit goal. Perfect for pricing, business planning, and cash-flow forecasting. No signup required.
Rent, insurance, software — costs that don't change with sales (use GST-exclusive figures).
Materials, freight, fees — costs that rise with each sale.
Break-Even Units
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Break-Even Revenue
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Your break-even point is the level of sales where total revenue exactly covers total costs, so you make neither a profit nor a loss. Knowing it tells you the minimum you must sell to keep the lights on — and every sale beyond it is profit.
The calculation only works when your selling price is higher than your variable cost per unit. If it isn't, every sale loses money and you can never break even no matter how much you sell — you'd need to raise your price or cut your variable costs first.
Say you run a small business with $50,000 of fixed costs per year (rent, insurance, software), you sell a product for $100, and each unit costs you $40 in materials and freight. Your contribution margin is $100 − $40 = $60 per unit. Break-even units = $50,000 ÷ $60 = 834 units (rounded up), which is 834 × $100 = $83,400 in sales. Sell more than 834 units and you start making a profit of $60 for every extra unit.
To work out how many units you need for a profit goal rather than just breaking even, add your target profit to your fixed costs before dividing: units for target profit = (fixed costs + target profit) ÷ contribution margin per unit. Targeting $30,000 profit in the example above needs ($50,000 + $30,000) ÷ $60 = 1,334 units, or $133,400 in sales.
Fixed costs stay the same no matter how much you sell — rent, insurance, subscriptions, loan repayments, and salaried wages. Variable costs rise and fall with each sale — materials, stock, packaging, freight, payment fees, and direct labour. Use GST-exclusive figures throughout if you are registered for GST, because the GST you collect is remitted to the ATO and isn't yours to keep.
Break-even units = total fixed costs / (selling price per unit − variable cost per unit). The denominator is your contribution margin per unit — the amount each sale contributes towards covering fixed costs. Multiply the break-even units by the selling price to get your break-even revenue (sales dollars). For example, with $50,000 of fixed costs, a $100 selling price and $40 of variable cost per unit, you break even at $50,000 / ($100 − $40) = 834 units, or about $83,400 in sales.
The break-even point is the level of sales at which your total revenue exactly equals your total costs (fixed plus variable), so your profit is zero. Below it you make a loss; above it you make a profit. It can be expressed in units (how many you need to sell) or in revenue (the sales dollars you need to bring in).
Contribution margin is your selling price per unit minus your variable cost per unit — the slice of each sale left over to cover fixed costs and then generate profit. If your price is $100 and variable cost is $40, your contribution margin is $60 per unit, or 60% as a ratio. Break-even revenue equals fixed costs divided by the contribution margin ratio.
Fixed costs stay roughly the same regardless of how much you sell — rent, insurance, software subscriptions, loan repayments, and salaried wages. Variable costs change with each unit sold — materials, stock you buy in, packaging, freight, payment processing fees, and direct labour or contractor costs tied to the job. Classify your costs first, because the split drives the whole calculation.
Use GST-exclusive figures throughout for a true break-even, because the GST you collect on sales is not your money — you remit it to the ATO. If you are registered for GST, enter your selling price and costs net of GST so the result reflects the cash you actually keep. Keep all three inputs (fixed costs, price, variable cost) on the same GST basis.
Add your target profit to your fixed costs, then divide by the contribution margin per unit: units for target profit = (fixed costs + target profit) / (selling price − variable cost). Switch on the target-profit toggle above and the calculator does this for you, showing both the units and the revenue needed to hit your profit goal.
Sources & methodology
This calculator uses the standard break-even formula: break-even units = total fixed costs / (selling price per unit − variable cost per unit), where the denominator is the contribution margin per unit. Break-even revenue = break-even units × selling price. The optional target-profit mode adds your target profit to fixed costs before dividing. Units are rounded up to the next whole unit because a partial sale won't fully clear your costs. Everything is computed in your browser — nothing you enter is stored or sent to a server.
Authoritative sources
Reviewed by Bishal Shrestha — Founder of OneBookPlus, 10+ years building tools with Australian tax-agent and BAS-agent practices. Last reviewed and updated: June 2026.
Disclaimer: This tool provides estimates only and is not professional advice. For decisions that affect your tax, finances, or compliance position, consult a registered professional.
OneBookPlus handles invoicing, GST tracking, BAS prep, and ATO lodgement automatically.