Key takeaways
- Break-even = the sales volume where you stop losing money and start making it.
- It's driven by your contribution margin (price − variable cost).
- The tool also finds target-profit units, margin of safety, and a price goal-seek.
- Runs from three inputs — zero dependencies, nothing to install.
- Free, open-source (MIT), downloadable from GitHub.
Excel Break-even & Scenario Planner is a free, open-source tool that answers the questions Excel's Goal Seek and Data Table make you fight for. From three inputs — fixed cost, price, and variable cost — it instantly gives you your break-even point, the units needed to hit a profit goal, your margin of safety, and even solves for the price you'd need to charge. No formulas to wire up, no add-ins.
What break-even really tells you
Every product carries two kinds of cost: fixed costs that don't change with volume (rent, salaries, software) and variable costs that scale with each unit sold (materials, shipping, transaction fees). Each sale contributes its price minus its variable cost toward covering those fixed costs. That gap is your contribution margin, and it's the engine of the whole analysis.
Your break-even point is simply how many units it takes for total contribution to cover total fixed cost. Sell one more and you're in profit; one fewer and you're in the red. It's the single most useful number for pricing a product, evaluating an idea, or deciding whether a volume target is realistic — and it's the number people most often compute wrong in a rushed spreadsheet.
Everything the planner calculates
| Output | Question it answers |
|---|---|
| Break-even units & revenue | "How much must I sell just to cover costs?" |
| Target-profit units | "How many units to make $X profit?" |
| Margin of safety | "How far above break-even is my expected volume?" |
| Price goal-seek | "What price do I need to hit my profit goal at this volume?" |
| Scenario table | "What's my profit across a range of sales volumes?" |
How to download & set up (about 1 minute)
Free and open-source on GitHub, with zero dependencies — nothing to
pip install. You just need Python 3.9+.
- Download the code (or Code → Download ZIP on GitHub):
git clone https://github.com/Synth88Labs/excel-breakeven-analyzer.git cd excel-breakeven-analyzer - Run it with your numbers — fixed cost, price, and variable cost (add a target profit
and expected volume for the full picture):
python breakeven.py --fixed 10000 --price 50 --varcost 30 --target 5000 --units 800 - Or solve for price — the price you'd need to earn a target profit at a given volume:
python breakeven.py --fixed 10000 --price 50 --varcost 30 --units 1000 --goal-seek-price 5000
⬇️ Get Excel Break-even & Scenario Planner on GitHub (free)
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A worked example
A product with $10,000 fixed cost, a $50 price, and $30 variable cost, expecting to sell 800 units:
python breakeven.py --fixed 10000 --price 50 --varcost 30 --target 5000 --units 800
Break-even & Scenario Planner
Contribution margin: 20.00/unit (40% of price)
BREAK-EVEN: 500.0 units (revenue 25,000.00)
For 5,000 profit: 750.0 units (revenue 37,500.00)
At 800 units: profit 6,000.00 | margin of safety 300.0 units (38%)Each unit contributes $20, so it takes 500 units to break even and 750 to make $5,000. At the expected 800 units, the business earns $6,000 and sits a comfortable 38% above break-even — meaning sales could fall by more than a third before it starts losing money. And if you needed $5,000 profit at 1,000 units, the goal-seek shows the price only needs to be $45. Every one of those answers came from a single command.
Who should use it
- Founders & small businesses — pressure-test an idea before committing.
- Product & pricing managers — find the price or volume that makes a product work.
- Freelancers — figure out how many projects cover your fixed monthly costs.
- Students & educators — a clean, transparent take on the CVP model.
Frequently asked questions
Is Excel Break-even & Scenario Planner free?
Yes — open-source under the MIT license, free for personal and commercial use.
What is the break-even formula?
Break-even units = fixed cost ÷ contribution margin, where contribution margin = price − variable cost. The tool does this and several related calculations for you.
What is margin of safety?
How far your expected sales sit above the break-even point, as units and a percentage. A higher margin means more cushion before you'd start losing money.
How is this better than Excel's Goal Seek?
Goal Seek solves one variable at a time and leaves no reusable artifact. This tool returns every answer at once, is reproducible, and can export a scenario table — no manual formula wiring.
Do I need to install anything?
Just Python 3.9+. The tool has zero third-party dependencies.
Can it handle a range of sales volumes?
Yes — it builds a scenario table of profit across volumes, which you can write to CSV with
-o and chart in Excel.
Summary
Break-even is the number that tells you whether a product can actually work — and it's too important to fumble in a one-off spreadsheet. Excel Break-even & Scenario Planner turns three inputs into your break-even point, profit targets, margin of safety, and the price you'd need to charge, free and open-source. Download it and stress-test your pricing in under a minute.