Break-even point

The break-even point is the moment when total costs equal total revenue, savings, or benefits — producing zero net gain or loss. Beyond the break-even point, a decision starts to deliver positive value; before it, the decision is still in deficit.

Where break-even analysis is used

• Buy vs rent decisions — at what point does buying a home cost less than continuing to rent?
• Refinancing decisions — how long must a borrower stay in a loan for refinancing fees to be recovered?
• Capital investment decisions — when does the cost of new equipment pay back through productivity gains?
• Subscription decisions — when does an annual prepay save money versus a monthly subscription?

Formula

Break-Even Point = Fixed Costs ÷ (Per-Unit Revenue − Per-Unit Variable Cost)

For non-business decisions, the formula is conceptually similar — divide the upfront cost by the periodic saving or return.

Example

A homeowner refinances a $400,000 mortgage to save $200 per month, with $4,000 in switching costs:

Break-even = $4,000 ÷ $200 = 20 months.

If the homeowner expects to keep the loan for at least 20 months, refinancing pays off. If they plan to sell or refinance again within that window, the cost is not recovered.

Why break-even matters

• Separates short-term cost from long-term gain — many decisions look bad in month one but pay off over years
• Reveals the time horizon required — break-even reveals how long a commitment must hold to be worthwhile
• Sensitises decisions to assumptions — small changes in the inputs often shift the break-even by months or years
• Aligns with opportunity cost — comparing break-even periods across alternatives reveals which decision pays off fastest

A robust break-even calculation should be paired with sensitivity analysis: vary the key inputs by realistic amounts and observe how the break-even shifts. Opportunity cost must also be factored in — the funds tied up before break-even could have produced returns elsewhere.