How to use this MER Calculator

Enter your total revenue and total marketing spend for any time period. The calculator shows whether your marketing budget generates more revenue than it costs – your baseline check before worrying about profit margins or attribution models.

What is MER? (Marketing Efficiency Ratio)

Marketing Efficiency Ratio is total revenue divided by total marketing spend (Total Revenue ÷ Total Marketing Spend). It shows whether your entire marketing budget generates more money than it costs.

When to use MER

MER is your survival metric when platform-specific ROAS looks terrible. If Meta reports 1.5x ROAS but your MER shows 3-4x, you’re still profitable – just not according to Meta’s attribution model.

This is the metric that matters when attribution breaks down. Platform ROAS tells you what each channel claims credit for. MER tells you whether your total marketing spend is financially viable, regardless of which platform wants credit.

It’s not about optimism – it’s about survival. When individual channel performance looks weak but you’re still generating revenue, MER shows whether you can justify continued spend.

MER vs ROAS vs ROI

MER includes all marketing spend – typically everything under your marketing budget line. Often called “blended ROAS.”

ROAS is platform-specific ad spend only. Breaks down into Meta ROAS, Google ROAS, Native ROAS, etc. Shows: “For every £1 I spent on Meta ads, I generated £X in revenue.”

ROI includes everything: ad spend, creative production, agency fees, software costs, staff salaries, product costs. Shows: “After paying for all business costs, here’s my actual profit.”

Example:

• ROAS: “£1 to Meta = £2 revenue”
• MER: “£1 total marketing spend = £3.50 revenue”
• ROI: “£1 all-in business cost = £0.10 profit”

Limitations of MER

MER shows revenue coverage, not profit. Like ROAS, it ignores unit economics and profitability. You can have strong MER while losing money on every sale.

Use MER as your baseline check: “Am I generating more revenue than marketing costs?” Not as proof of profitability.

More Calculators:
CAC Calculator: Calculate how much to generate one single customer
ROAS: What is your ad spend giving you?