--- title: "MER, nCAC and Marketing ROI Calculator | Product Metrics" description: "Free MER and CAC calculator: enter revenue, marketing and ad spend, orders and new customers to get MER, nCAC, blended ROAS, cost per order and marketing ROI." canonical: "https://www.productmetrics.io/mer-calculator" pageType: feature language: en publisher: "Product Metrics" dateModified: 2026-10-07 --- > Content index: https://www.productmetrics.io/llms.txt # MER and nCAC calculator This calculator turns your account totals into your marketing efficiency ratio (MER) and your new customer acquisition cost (nCAC). It also gives blended ROAS and cost per order, and, with a contribution margin, first-order profit and marketing ROI. _MER and blended ROAS use revenue as entered, the basis of your ad platform. Profit and ROI use revenue excl. VAT, so enter your VAT rate if revenue includes it._ ## Every step behind the numbers, worked through for the start values. Illustrative data. An example shop made €50,000.00 revenue (excl. VAT, so the VAT rate is 0%) from 200 orders, 125 of them from new customers. It spent €10,000.00 on marketing, of which €8,000.00 was ad spend. Its contribution margin is 40%. | Step | Calculation | Result | | --- | --- | --- | | MER | €50,000.00 ÷ €10,000.00 | 5 | | Blended ROAS | €50,000.00 ÷ €8,000.00 | 6.25 | | Cost per order | €8,000.00 ÷ 200 orders | €40.00 | | nCAC | €8,000.00 ÷ 125 new customers | €64.00 | | Average order value | €50,000.00 ÷ 200 orders | €250.00 | | First-order profit | €250.00 × 40% | €100.00 | | First-order profit minus nCAC | €100.00 − €64.00 | €36.00 | | Marketing ROI | (€50,000.00 × 40% − €10,000.00) ÷ €10,000.00 | 100% | Every €1.00 of marketing brought €5.00 of revenue. A new customer cost €64.00 in ads and a first order earns €100.00 of profit, so €36.00 is left after winning the customer. After product costs, the €10,000.00 of marketing earned €10,000.00 on top of its own cost: a marketing ROI of 100%. ## Six numbers, and the decision each one informs. - **MER.** Total revenue ÷ total marketing spend: the revenue each €1.00 of marketing brings, across every channel. Decision: whether total marketing spend can grow, read against 1 ÷ your margin. - **Blended ROAS.** Total revenue ÷ ad spend. Read it next to the ROAS your ad platform reports. Decision: whether ad spend is keeping pace with revenue. - **Cost per order.** Ad spend ÷ orders, new and returning together. Decision: whether an average order earns more than its ads cost. - **nCAC.** Ad spend ÷ new customers: what winning one new customer costs in ads. Decision: how much a new customer may cost before acquisition stops paying. - **First-order profit minus nCAC.** Average order value × margin, minus nCAC. Positive means a new customer pays for itself on the first order. Decision: how much repeat buying a push for new customers relies on. - **Marketing ROI.** (Revenue excl. VAT × margin − marketing spend) ÷ marketing spend. 0% is break-even. Decision: whether to increase or lower the marketing budget. This calculator works on account totals. Product Metrics shows nCAC per product and as an average. - [How Product Segmentation works](https://www.productmetrics.io/product-segmentation) - [How Full Signal Tracking works](https://www.productmetrics.io/server-side-tracking) ## What MER cannot tell you, and what to read next to it. - **Which channel works.** MER blends every channel. Use channel and campaign ROAS to decide where to increase or lower priority. - **Which products earn their spend.** An account-wide ratio hides products that lose money. Margins differ per product, and so does the return that pays for them. - **New or returning.** A healthy MER can come from repeat buyers while new customers dry up. Read it together with nCAC. - **How accurate the inputs are.** Product Metrics is not an attribution tool. Every number here depends on the orders and new customers your shop and ad platform recorded. ## MER and nCAC questions, answered. ### What is a good MER? There is no universal number: it depends on your margin. Marketing pays for itself when MER reaches 1 ÷ your contribution margin, with revenue excl. VAT. That is a MER of 2.5 at a 40% margin and 4 at 25%. A good MER is above that line by enough to cover fixed costs and the profit you want to keep: at a 40% margin, a MER of 5 spends 20% of revenue on marketing and leaves 20% before fixed costs. ### What is the difference between MER and ROAS? ROAS divides the revenue an ad platform credits to its ads by the ad spend. MER divides all revenue by all marketing spend, whatever drove it. In the example, blended ROAS (total revenue ÷ ad spend) is 6.25 and MER is 5, because MER also counts the €2,000.00 of marketing that is not ad spend. ### How do you calculate nCAC? Divide ad spend by new customers: €8,000.00 ÷ 125 = €64.00. Count only customers who had not bought before. Then compare it with the profit on a first order: with an average order of €250.00 and a 40% margin that is €100.00, so €36.00 is left after nCAC. ### Is marketing ROI the same as ROAS? No. ROAS is revenue ÷ ad spend and leaves product cost out. Marketing ROI is profit after product cost ÷ marketing spend. The same MER of 5 is a marketing ROI of 100% at a 40% margin and 0% at a 20% margin. ## Embed this calculator Paste this script tag into your own page to show the calculator there, with the same maths and no sign-up. It fits the width of your page, resizes with the calculator and follows the visitor’s light or dark setting. The script adds the calculator and a link to the full version under it. Keep the attribution link: it credits the calculator. `` ## Related pages. - [ROAS, MER, POAS and nCAC: which metric to use](https://www.productmetrics.io/blog/marketing-efficiency-ratio-vs-roas): Which metric answers which question. - [Customer acquisition cost for ecommerce](https://www.productmetrics.io/blog/customer-acquisition-cost-formula): What a new customer costs, and what you can pay for one. - [LTV:CAC ratio for ecommerce](https://www.productmetrics.io/blog/ltv-cac-ratio-ecommerce): Why LTV has to be profit, and how to derive your own ratio. - [Incrementality testing for Google Shopping](https://www.productmetrics.io/blog/incrementality-testing): Whether the ads caused the revenue MER counts. - [Break-even ROAS calculator](https://www.productmetrics.io/break-even-roas-calculator): The ROAS your products need to make a profit. - [CAC](https://www.productmetrics.io/glossary/cac): Customer acquisition cost, defined, with an example. - [ROAS](https://www.productmetrics.io/glossary/roas): Revenue per €1.00 of ad spend, and what it leaves out. - [Marketing ROI](https://www.productmetrics.io/glossary/marketing-roi): Profit on marketing spend, not revenue. - [Contribution margin](https://www.productmetrics.io/glossary/contribution-margin): The margin to enter above. - [Product Segmentation](https://www.productmetrics.io/product-segmentation): Segment products by advertising clicks and return. ## See which products earn their ad spend, and which don’t. Product Metrics segments your products by advertising clicks and return against your target, then writes each segment to a Merchant Center label your campaigns use. - [Analyse your products for free](https://app.productmetrics.io/): Log in with Google, no credit card --- Published by Product Metrics (Berend Vrakking, founder). HTML version: https://www.productmetrics.io/mer-calculator