How to run a break-even analysis for a startup

A break-even analysis startup teams can defend answers one question: how many units (or how much revenue) cover fixed costs after each sale pays its variable cost. It is not a full forecast, not gross-margin poetry, and not a promise that cash arrives when the P&L crosses zero. Nautis has no Break-Even module. You build the worksheet from price, variable cost, and fixed costs, then optionally mirror the same assumptions in Financial Planner. Operating guidance only, not accounting or investment advice.

What break-even analysis startup founders should compute

Contribution per unit equals unit price minus variable cost per unit. Break-even units equal fixed costs divided by contribution per unit, when contribution is positive. Break-even revenue equals break-even units times price, or fixed costs divided by contribution margin ratio (contribution divided by price).

Write the three inputs before any chart:

1. Price you actually charge for one unit (or one month of a subscription treated as a unit).
2. Variable cost that moves with that unit (materials, delivery, usage COGS, payment fees tied to the sale).
3. Fixed costs for the period (salaries, rent, base tools) that you will pay even if volume is zero.

Illustrative toy math (composite only): price $100, variable cost $40, contribution $60, fixed costs $12,000 per month. Break-even units = 12,000 / 60 = 200 units that month. Break-even revenue = $20,000.

Show the arithmetic in the Note so a new hire can recompute without a meeting. Hidden spreadsheet macros are not a break-even analysis.

If contribution is zero or negative, stop. No volume fixes a unit that loses money before fixed costs.

Subscriptions need an extra honesty check: if you count annual prepay as one unit, variable costs and fixed costs must use the same annual window, or convert everything to monthly. Mixing an annual price with monthly fixed costs understates break-even units.

Split fixed and variable without wishful coding

Mis-split costs fake break-even. Put every material cost on a scorecard once.

Revisit the split monthly. Accounts receivable timing does not change whether a cost is fixed or variable; cash delay is a different problem.

When a cost is truly mixed, split the line: base hosting as fixed, metered overage as variable. A single blended number that changes every week will make break-even bounce for no operational reason.

Period discipline

Pick month or year and stay there. Mixing annual fixed costs with monthly prices invents a fantasy break-even. State the period on the worksheet title.

Put the owner initials and the refresh date on that title line too. Orphan worksheets without dates become folklore by the next board meeting.

Build the one-page worksheet

Columns that matter:

• SKU or plan name
• Price
• Variable cost per unit
• Contribution per unit
• Fixed cost pool for the period (shared or allocated)
• Break-even units
• Break-even revenue
• Current run-rate units
• Gap (break-even units minus run-rate)

One product first. Multi-SKU companies either compute per SKU with an allocated fixed pool or use a weighted average contribution you can explain in one sentence. Hidden cross-subsidies belong in Notes, not in silence.

If two SKUs share one fixed team, allocate fixed costs with a written rule (percent of revenue, percent of units, or equal split) and keep that rule for the quarter. Quiet reallocation is how every product looks fine while the company does not.

Illustrative worksheet row (composite only): Pro plan $80/month, variable $15, contribution $65, monthly fixed pool $19,500, break-even 300 subscriptions, current 220, gap 80.

Mirror the same numbers in Financial Planner

On Revenue Items, enter Name, Unit price, billing frequency, forecasted units, and Cost of goods sold per unit when it applies. On Model Inputs, enter Operating Expenses that match the fixed pool you used on the worksheet. Profit & Loss is calculated: revenue, COGS, gross profit, operating expenses, and further down the statement. If break-even on paper says 200 units and the P&L still looks deep red at 200, your fixed or variable split drifted between the worksheet and the model.

There is no separate scenario button. Clone the project, rename it, and change price, units, or expense lines. Use Compare when you want two projections side by side. Typical clones for break-even work: price down 10%, variable cost up 10%, fixed hiring delayed one quarter.

Build inputs in order the product expects: Revenue Items first, then Model Inputs, then read Profit and Loss. If a P&L line looks wrong, fix the source tab rather than typing over calculated cells. Shared Access lets a co-founder or accountant edit the same project; still keep the paper worksheet as the tie-breaker when debates start.

Keep Notes in the planner documenting the break-even formula and the period. Investors read Notes when the Dashboard looks tidy.

For cash runway after the model exists, keep Startup Health Cash Balance and burn honest, and see How to calculate startup burn rate and runway. Hitting break-even on contribution does not refill a bank account if customers pay late.

Import historical revenue into Revenue Items only when it improves the unit forecast, not to decorate the worksheet. Break-even still needs a clean price and variable cost even if the import fills volume history.

Sensitivity steps that beat a single magic number

Change one input at a time and record break-even units.

Illustrative sensitivity (composite only): base break-even 200 units; price -10% lifts break-even to 240; one support hire adds $5,000 fixed and lifts break-even to about 283 on the same contribution.

Stop when a step needs a miracle volume your pipeline cannot name. Break-even analysis startup teams skip is usually this table, not the first formula.

Share the sensitivity table with whoever owns pricing and hiring. A break-even number that never meets a discount request or a headcount ask is stationery. The point of the steps is to force a decision while contribution is still positive.

Illustrative quarter at Pinecart

Illustrative Pinecart (composite only): ships a hardware accessory with consumable refills.

Month 1: worksheet shows break-even 1,100 devices at current price and COGS; fixed includes three salaries and rent. Run-rate 640. Month 2: they refuse a discount campaign after sensitivity step 1 blows break-even past 1,400. Variable packaging cost corrected upward after a supplier quote. Month 3: clone in Financial Planner with delayed fourth hire; Dashboard gross margin and P&L checked against the worksheet; gap closes to 180 units on a modest price rise for the refill SKU only.

They did not confuse break-even with "profitable forever." They used it to reject a discount and to time a hire.

Pinecart also wrote the period on every export: monthly worksheet beside a cloned three-year planner project labeled with the same contribution assumptions. When a contractor proposed a bundle price, they ran sensitivity step 1 before the sales call, not after the invoice went out.

What break-even will not tell you

It will not fix unpaid invoices, inventory cash locks, or tax remittances. It will not replace unit economics across cohorts, or a gross-margin boundary review for what belongs in COGS. It will not bless a negative contribution product.

It also will not choose your price for you. The worksheet only shows how many units the current price and cost structure require. If that volume is unreachable, change price, variable cost, or fixed cost on purpose, then recompute. Hoping the Dashboard alone will invent contribution is how teams stall.

Use it to set a floor volume, to test pricing and hiring, and to keep Financial Planner assumptions tied to a formula you can recompute on paper in two minutes. When the worksheet and the cloned projections disagree, trust neither until the split and period match.

Name an owner for the monthly refresh. Unsigned break-even slides rot into decoration. Signed worksheets change prices and hiring dates.

Refresh after any price change, COGS change, or material hire. Skip vanity redesigns of the sheet layout. The only read that matters is whether gap-to-break-even is shrinking for reasons you can name: volume, price, variable cost, or fixed cost.

Keep the calculator boring on purpose. Fancy charts that hide the fixed and variable split are not progress.