The detailed guide below is currently available in English.
The break-even math
Every sale first pays for the cost of making that one item; whatever remains is the contribution margin that chips away at fixed costs. Break-even happens when enough margins have accumulated to cover the fixed block: fixed costs ÷ contribution margin per unit. A $20 margin against $10,000 of fixed costs needs exactly 500 sales — each sale after that drops the full $20 to the bottom line.
Using break-even to make decisions
Break-even is a lever you can pull from either side. Raising price widens the margin and lowers the units needed, but usually costs some volume; trimming the variable cost (a cheaper supplier, less waste) does the same without touching the shelf price. Cutting fixed costs lowers the bar outright. Compare the units required against realistic demand — a break-even point the market cannot support is a signal to redesign the plan, not to try harder.
Contexto local: Portugal
Dados locais essenciais para cálculos financeiros em Portugal — diferem dos valores padrão dos EUA:
- IVA: Taxa normal 23 % (continente), intermédia 13 %, reduzida 6 %. Os preços ao consumidor já a incluem.
- IRS (2025): Taxas progressivas de 13,25 % a 48 %, mais taxa solidária e majoração ACR (Açores e Madeira têm deduções próprias).
- Segurança Social: Taxa contributiva global 34,75 % — 11 % a cargo do trabalhador sobre o bruto, 23,75 % da entidade patronal.
- Salário mínimo 2025: 870 € por mês, pagos em 14 prestações (12 + subsídios de férias e de Natal).
- Gorjeta: Não é obrigatória; 5–10 % em restaurantes é bem-visto.
Atualizado: outubro 2026 · valores de 2025, fontes oficiais acima.
Perguntas frequentes
What counts as a fixed cost?
Costs that do not move with each sale over the period: rent, salaries, insurance, software subscriptions, loan payments. A cost that only appears when you produce a unit belongs in the variable column.
Why round the break-even units up?
A fraction of a sale cannot cover its share of fixed costs, so 500.2 units still means 501 sales in practice. The exact figure is shown too, since it is the one to use for revenue math.
Can I use this for a service business?
Yes — treat each engagement or client hour as a “unit.” Fixed costs are your monthly overhead, price is the fee, and variable costs are whatever delivering that unit costs you.