Bath · Bristol · London
Profit calculator

Marketing Efficiency Ratio (MER) Calculator

MER, the marketing efficiency ratio, is total revenue divided by total marketing spend, across every channel and every fee.

Nic Crane · FounderFreeFormula on the page
Marketing efficiency ratio calculator

Nothing you enter leaves your browser.

The share of each sale left after the cost of the product
Your MER—
Break-even MER at this margin—
Gross profit left after marketing—

Enter your figures to see the result.

It ignores attribution entirely: no platform can claim a sale twice in it, which makes it the check a finance team can rely on when the platforms disagree. Break-even MER is one divided by your gross margin.

The formula

  • MER=total revenue ÷ total marketing spend
  • Break-even MER=1 ÷ gross margin
  • Gross profit after marketing=total revenue × gross margin − total marketing spend

Why MER is the finance check

Every ad platform reports the sales it can connect to its own ads, and the reports overlap: Google, Meta and Microsoft can each claim the same order. MER uses the till, not the platforms. If the platforms' combined claims rise while MER falls, that is a sign the advertising is being credited with sales it did not add.

What MER cannot tell you

MER includes every sale, including those that would have happened with no marketing at all, so it says nothing about which channel is working. Use it as the check on the whole, and an incrementality test to judge each channel.

Common questions

The questions that come up.

How is MER different from ROAS?

ROAS divides the revenue one platform credits to its ads by that platform's spend. MER divides all revenue by all marketing spend. ROAS can be inflated by overlapping credit; MER cannot.

What is a good MER?

One above your break-even MER by enough to cover the overheads marketing does not already include. Break-even MER is one divided by gross margin: at a 40% margin it is 2.5.

Should MER include agency fees?

Yes. MER is meant to capture the whole cost of marketing, so include fees, tools and any production costs alongside media spend.

Read next

Where to go from here.

Guide

Is your advertising profitable? A checklist for CFOs

Read
Calculator

ROAS calculator

Open
Calculators

Every calculator

ROAS, POAS, MER, ACoS and cost per lead, each with its formula shown.

Browse
Your own accounts

Numbers that do not add up in your own accounts?

A review starts by checking what the platforms are being told, and whether it matches the books.

Speak with NicEvery guide
The Crane Standard

The senior read,
once a week.

Most marketing newsletters are noise on a schedule. This is not that. Once a week I send a short, considered read on the shifts that actually change what you should do, across the AI shift, PPC, technical SEO and analytics. Filtered, weighted and signed off by me before it goes out. The judgement is mine, and now you can hear every edition in my own voice.

Nic CraneFounder, The Crane Consultancy

Topics you want

All three lands every Tuesday. Choose a selection and you get only those, as and when they publish, always on a Tuesday.

One considered email a week, edited and signed off by Nic. No filler, no sharing, unsubscribe in a click. By subscribing you agree to our Privacy Policy.

Prefer LinkedIn? Subscribe on LinkedIn instead, the same edition, delivered by push and email.