RunLocalTools

Ad Spend Break-Even Calculator — Break-Even ROAS, CPA & Conversion Rate

Free ad break-even calculator: find your break-even ROAS, max CPA and minimum conversion rate for e-commerce, lead-gen or subscriptions. Runs in your browser.

What it does

This calculator tells you the exact point where your ads stop losing money. Enter what a sale is worth, what it costs you to fulfil it, and what your clicks cost, and it returns your break-even ROAS, the most you can pay per sale (break-even CPA), the minimum conversion rate you need at your current cost per click, and the maximum CPC or CPM you can afford at your current conversion rate.

It handles three business models in one tool: one-off e-commerce orders, lead generation with a close rate, and subscriptions where lifetime value decides how much you can spend to win a customer.

How it works

Everything is contribution-margin arithmetic, done in your browser — nothing is uploaded.

The core formulas

  • Contribution per sale = revenue after VAT and refunds − product cost − shipping and handling − payment fees.
  • Break-even CPA = contribution per sale. Spend more than this to win a customer and that sale loses money.
  • Break-even ROAS = revenue the ad platform reports ÷ break-even CPA.
  • Break-even conversion rate = your CPC ÷ break-even CPA.
  • Maximum CPC = break-even CPA × your conversion rate. On a CPM basis, break-even CTR and maximum CPM are solved the same way.

The three models

  • E-commerce: price (optionally VAT-inclusive), product cost, shipping, handling, percentage and fixed payment fees, and your refund rate.
  • Lead generation: revenue per customer, delivery cost, and the share of leads that close. Value per lead is contribution per customer × close rate.
  • Subscription: monthly price, gross margin, payment fees and monthly churn produce customer lifetime value (or value over a fixed horizon of months). The tool also shows CAC payback in months and your LTV : CAC ratio; once you know your payback period, you can project what recurring revenue compounds to with the Compound Interest Calculator.

Targets, not just break-even

Break-even is the floor. Switch the goal to a target profit per sale, a target margin, a target ROAS or (for subscriptions) a target LTV : CAC, and every figure — max CPA, required conversion rate, max CPC — is recalculated for the profit you actually want.

How to use it

  1. Pick your model: E-commerce, Lead-gen or Subscription.
  2. Enter the economics of one sale (price, costs, fees, refund rate — or close rate and delivery cost for leads).
  3. Enter your ad funnel: CPC (or CPM and CTR) and your click-to-sale conversion rate.
  4. Optionally set a profit target and an ad budget with fixed costs to get a forecast.
  5. Read the verdict at the top, then use the sensitivity table and chart to see how much room you have.
  6. Use + Scenario to compare up to three setups side by side, e.g. today’s price versus a 10% price rise.
  7. Copy the summary, or download the sensitivity grid (.csv) or your scenarios (.json).

What you get beyond the basic maths

  • Sensitivity heat-map: net profit across a grid of CPC and conversion-rate values, green for profit and red for loss, with your current setup outlined.
  • Profit-vs-conversion-rate chart with your break-even point marked.
  • Budget forecast: clicks, sales, revenue and net profit for a given ad budget, plus how much you must spend to cover fixed costs.
  • Plain-English verdict that tells you whether you are above or below the line, and by how much.
  • Guard rails: if your margin is zero or negative the tool says no conversion rate can rescue it, and impossible inputs such as a conversion rate above 100% are flagged instead of producing nonsense.

Privacy

Your figures never leave your device. Inputs are remembered in your own browser so they are still there next visit, and you can reset a scenario at any time.

FAQ

What is a good break-even ROAS?

There is no universal number — it depends entirely on your margin. If each sale leaves you 40% of the price after product, shipping, fees and refunds, your break-even ROAS is 1 ÷ 0.40 = 2.5×. The lower your margin, the higher the ROAS you need just to stand still.

Why is my break-even ROAS higher than I expected?

Usually because of costs that don’t show up in the ad account: refunds, payment fees, shipping and VAT. This calculator subtracts all of them before working out what you can afford to pay for a customer.

Does ROAS here match what Meta or Google Ads report?

It uses the same definition: the purchase value the platform reports divided by ad spend. If your prices include VAT, tick the VAT box so profit is calculated on the net amount while ROAS still uses the price the platform sees.

Can I spend more than break-even on ads?

Yes, in two cases. If you sell subscriptions or repeat purchases, lifetime value can justify paying more than the first sale earns — use the Subscription model. And if you have a strategic reason to buy customers at a loss, the forecast shows exactly how much that costs.

How is this different from a general break-even calculator?

A general tool works from fixed costs, variable costs and price to find the number of units to sell. This one starts from an ad account: it turns your unit economics into the CPA, ROAS, CPC and conversion-rate limits you can check against your dashboard. For units-to-break-even on fixed costs, use the Break-Even Point Calculator.

I sell a service, not a product — what do I enter?

Use the Lead-gen model with your revenue per client, and work out the price itself first: the Freelance Hourly Rate Calculator turns a target income and billable hours into a minimum rate.

What if I only know my margin percentage, not each cost?

Enter your price and put the whole cost in the product-cost field (price × (1 − margin)), leaving shipping, handling and fees at zero.