Break-Even Calculator

What this does

Fixed costs, a price and a unit cost give you the volume where the business stops losing money. This also gives the contribution margin, the volume needed for a profit target, and what any volume you enter actually earns.

Why this one

It refuses to answer when the answer is a lie. If each unit sells for less than it costs to make, there is no break-even volume: selling more makes the loss bigger. A calculator that returns a negative number there, or a very large one, sends someone away planning to sell their way out of it.

The formula

contribution per unit  =  price  -  variable cost per unit
break-even units  =  fixed costs / contribution per unit
units for a target  =  (fixed costs + target profit) / contribution per unit

Published so you can check it. A calculator about money that will not show its working is asking to be trusted on the one thing you cannot verify.

Questions

What counts as a fixed cost?

Anything you pay whether or not you sell one more unit: rent, software, insurance, your own salary if you take one. Variable costs are the ones that only exist because a sale happened, such as materials, shipping and payment processing fees.

Where do payment processing fees go?

In variable costs. They scale with sales, and at roughly 3% they matter more than most people allow for on a low margin product.

Why does it sometimes refuse to give a number?

Because there is no volume that breaks even when each sale loses money or exactly covers itself. The honest output there is the reason, not a number.