How to calculate your break-even point and break-even date

The calculation relies on sorting costs by how they behave when activity changes:

• Variable costs follow the volume sold: purchases of goods and materials, subcontracting, commissions, delivery costs.
• Fixed costs stay stable over the period, whatever the volume: rent, insurance, subscriptions, overhead salaries, depreciation.

Some costs are mixed, such as a plan with overage charges or energy partly tied to production: record their fixed and variable parts separately.

The contribution margin is what is left of revenue once variable costs are paid. It pays for fixed costs first, then for profit:

Contribution margin       = revenue excl. VAT − variable costs
Contribution margin ratio = contribution margin / revenue × 100

Bpifrance Création and the French chambers of commerce give the same formula:

Break-even point = fixed costs / contribution margin ratio

Example. A small trading business forecasts for the year:

Contribution margin        = 500,000 − 300,000         = €200,000
Contribution margin ratio  = 200,000 / 500,000 × 100   = 40.00%
Break-even point           = 120,000 / 0.40            = €300,000
Margin of safety           = 500,000 − 300,000         = €200,000, i.e. 40.00% of revenue

Reading it: at €300,000 of revenue, the contribution margin exactly covers the €120,000 of fixed costs. Every euro sold beyond that brings in €0.40 of profit before tax. With €500,000 forecast, sales can fall by 40% before the business makes a loss.

If the contribution margin ratio is zero or negative, there is no break-even point: every sale costs more than it brings in, and selling more deepens the loss.

The break-even point is expressed in euros; the break-even date, in time. Bpifrance Création calculates it as follows:

Days to break even = break-even point / annual revenue × 360 or 365

360 or 365 days? The 360-day basis follows the commercial year of twelve 30-day months; 365 follows the calendar. In the example: 300,000 / 500,000 × 360 = 216 days, or × 365 = 219 days. The calculator offers both: keep the same basis from one year to the next.

The even-activity assumption. The formula assumes revenue is spread evenly over the financial year. On 365 days, for a year starting on 1 January, 219 days lead to 7 August. For a seasonal business that date is meaningless: add up revenue month by month and find the month in which the cumulative contribution margin exceeds the year's fixed costs.

A result above the chosen basis means the break-even point is not reached within the year: the margin of safety is then negative.

Three levers, all of which can be measured with the calculator:

1. Raise the contribution margin ratio: prices, purchasing terms, discounts. In the example, going from 40% to 45% lowers the break-even point from €300,000 to €266,666.67.
2. Cut fixed costs: €12,000 less rent brings the break-even point down to €270,000.
3. Sell more with the same structure: the break-even point does not move, but the margin of safety widens.

Conversely, a new hire or new premises increase fixed costs. Divide their annual cost by the contribution margin ratio to find the extra revenue required: a position costing €45,000 a year, at a 40% ratio, calls for €112,500 of additional sales.