Vocations · Professional Development

Find the sale where
profit starts.

Enter a price, what each sale costs you and what you pay every month no matter what. The page shows how many you have to sell to cover it all, draws the chart, and lets you test a higher price or a cheaper supplier before you commit.

Open the calculatorWhat you get

The calculator

The worked example is a made-up student business selling printed shirts at $18. Change any number, drag the handle on the chart, or pick another example from the menu.

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What you get

Vocations · Professional DevelopmentFree

What you finish with
The number of sales and the sales income at which a product or small business breaks even, the profit and margin of safety at the sales you expect, the sales needed to reach a profit goal, and the working written out for a class assignment or a plan.
Who it is for
High school and college students in business, entrepreneurship, economics and accounting classes; student-run enterprises and business clubs; teenagers and adults pricing a side business; teachers who want a live cost-volume-profit demonstration.
Format
Browser tool with three parts: break-even for one product with a chart and what-if sliders, break-even for a sales mix of up to four products, and saved setups side by side. Prints the result with its chart and working; downloads the numbers and the comparison as spreadsheets (.csv) and a file you can import later.
Access
Free. No account or sign-in. It runs in your web browser on a phone, tablet or computer. Everything you type stays in this browser and is saved there as you go; nothing is sent to Caveat.
Where it lives
The Professional Development space in Caveat Vocations.
Support
Questions, a correction or a request: team@caveatacademic.com.

How to use it

  1. Start with the shirt example, or choose Start blank and name what you sell.
  2. Enter the price, then list what each sale costs you and what you pay every period whatever you sell.
  3. Read the break-even point, then add the sales you expect and a profit goal. Drag the handle on the chart to see profit at any volume.
  4. Use the what-if sliders to test a price change or a cheaper supplier. Keep the change if you like it.
  5. Save each version under a name and compare them on the Saved tab, or print the one you choose.

Open the calculator

How break-even works

Cost-volume-profit analysis, in plain terms.

Two kinds of cost

Variable costs rise with every sale: the blank shirt, the ink, the bag, the card fee. Fixed costs are owed for the period whatever you sell: rent, equipment, software, insurance. Some costs are a mix of both, such as a phone plan with a base charge and usage fees. Put the base in fixed costs and the per-sale part with the unit costs.

The formulas

Contribution margin for one unit = price − variable cost of one unit. Break-even in units = fixed costs ÷ contribution margin. Break-even in sales = fixed costs ÷ contribution margin ratio, where the ratio is the margin divided by the price. Units for a profit goal = (fixed costs + the goal) ÷ contribution margin. Margin of safety = expected sales − break-even sales. Profit swing = total contribution margin ÷ profit: how many times as fast as sales the profit moves. The closer you are to break-even, the bigger it is.

With several products, the margin used is the average across the mix, weighted by how many of each you sell. That answer holds only while the mix holds.

What the model leaves out

The lines on the chart are straight. Real prices drop with discounts, unit costs fall when you buy in bulk, and fixed costs jump when you outgrow a space or a machine. The calculation also ignores income tax and counts your own time as free unless you enter a wage for it. Treat the result as a first test of a plan, and run it again when a number changes.

How it is checked

Every amount is held in whole cents, so nothing is lost to rounding. Before each release the calculator is run against exact fractions on 4,500 random cases and has to agree on every one.

One shirt sells for $18.00Its own costs $7.50Left over $10.50Fixed costs each month: $63060 shirts × $10.50 = $630Shirt 61 is the first one that earns a profit.
The idea in one picture. Part of every sale goes to the cost of the thing sold. What is left over, the contribution margin, pays the bills that arrive whether you sell anything or not. Break-even is the number of sales it takes for those leftovers to add up to the fixed costs.

Sources

  1. Franklin, M., Graybeal, P., & Cooper, D. (2019). Principles of Accounting, Volume 2: Managerial Accounting. OpenStax, Rice University. Chapter 3, Cost Volume Profit Analysis: contribution margin, break-even in units and dollars, target profit, sales mix and margin of safety.
  2. U.S. Small Business Administration. Break-even point, sba.gov/breakevenpointcalculator. Fixed costs ÷ (price − variable costs) = break-even point in units. Read November 10, 2026.

The examples are made up. A break-even estimate is only as good as the costs you enter; it does not include income or sales taxes, and it is not accounting, tax or legal advice. Before you spend real money, check your numbers with someone who knows your kind of business. Support: team@caveatacademic.com.