What is the marketing efficiency ratio (MER)?

Instead of judging one channel, the marketing efficiency ratio sets total revenue against total ad spend across every channel at once. It is also known as blended ROAS or total ROAS. Its advantage is the whole-business view that a channel ROAS structurally cannot give you.

What is the difference between MER and blended ROAS?

None. MER and blended ROAS are exactly the same calculation: total revenue ÷ total ad spend. «MER» became the common term after the iOS 14 attribution break because it stresses independence from tracking; «blended ROAS» is the more descriptive name. Anyone searching for either means the same metric.

How do you calculate MER, or blended ROAS?

MER = total revenue ÷ total ad spend. For example: $20,000 of revenue ÷ $8,000 of ad spend = an MER of 2.5x, or 250 %.

An MER of 3–5x is solid for most industries and margins. With high production costs or thin margins it should be closer to 5–8x. Expect the MER to sit below any channel ROAS, because it counts every marketing cost rather than one platform's.

Marketing Efficiency Ratio Calculator

Work out your marketing efficiency ratio — blended ROAS by its other name — and measure the return of your entire budget across every channel at once.

Total revenue (€) Total revenue across all channels Total ad spend (€) Total ad spend across all marketing channels

MER (ratio)

2.5x

total revenue ÷ ad spend

MER (%)

250.0 %

marketing efficiency as a percentage

Where your MER sits

0x 1x 2.5x 4x ≥ 5x

Loss zone Break-even Profitable

Gross margin (%)(optional)

The share of revenue left after the cost of goods. The MER calculator uses it to turn blended ROAS into a profit contribution.

→ Work it out here

Profit sensitivity

Current total profit

—

at the current budget and margin

Break-even total budget

—

Enter a gross margin

The curve assumes a constant MER. In reality efficiency usually falls as budgets rise sharply. Read it as orientation, not as a forecast.

Next step

Marketing Cockpit

Step up from the channel view and check your unit economics as a whole.

What the MER formula measures that a channel ROAS cannot

The marketing efficiency ratio (MER) — also called blended ROAS or total ROAS — divides total revenue by the total ad spend of every channel. Where a channel ROAS judges one platform in isolation, the MER judges the whole operation. That distinction stopped being academic with Apple's iOS 14 tracking restrictions: attribution models lost sight of large parts of the customer journey, and channel ROAS figures became correspondingly unreliable. The MER sidesteps the problem entirely, because it needs no tracking at all — only revenue and spend, both of which you already know exactly.

MER vs ROAS: same arithmetic, different denominator

Between MER and blended ROAS there is no difference at all. They are the same calculation: total revenue ÷ total ad spend. «MER» took hold in D2C and e-commerce after the iOS 14 attribution break because the name stresses independence from platform tracking; «blended ROAS» is the more descriptive term. Against a channel ROAS, though, the difference is real and it is the denominator: a channel ROAS counts one platform's spend against the revenue that platform claims, and since several platforms routinely claim the same conversion, their figures can add up to more revenue than actually occurred. The MER cannot do that. It only has one revenue number.

MER (blended ROAS) = total revenue ÷ total ad spend

To compare individual campaigns at channel level, use the ROAS calculator alongside this one.

Total revenue against total marketing spend

A shop splits $8,000 of ad spend across three channels and takes $20,000 in total revenue:

Google Ads$4,000

Meta Ads$3,000

TikTok Ads$1,000

Total spend$8,000

Total revenue (shop)$20,000

MER = 20,000 ÷ 8,000 = 2.5x

The platforms might report 6x ROAS on Google and 5x on Meta — which between them accounts for more than the $20,000 that actually came in. The MER shows what happened: 2.5x overall, regardless of who claims the conversion.

What is a good MER? It depends on your cost structure

Guide values by cost structure:

Solid (average margin)	3–5x
Higher fixed costs / thin margin	5–8x

The MER sits systematically below any channel ROAS, because it includes every marketing cost — organic channels and overhead among them. That is the point, not a shortcoming.

Budget, mix, and the marketing attribution problem MER sidesteps

Shift budget by contribution: Raise the share of channels that contribute most to total revenue — even where their channel-level ROAS is hard to measure, which is precisely where attribution fails you.
Strengthen unpaid channels: SEO, email and referral raise total revenue without raising spend, which improves the MER directly. No channel ROAS will ever show you this.
Optimise the conversion rate: Same traffic, more purchases — revenue rises with no additional ad budget at all.

Frequently asked questions

What is the marketing efficiency ratio (MER)?: Instead of judging one channel, the marketing efficiency ratio sets total revenue against total ad spend across every channel at once. It is also known as blended ROAS or total ROAS. Its advantage is the whole-business view that a channel ROAS structurally cannot give you.
What is the difference between MER and blended ROAS?: None. MER and blended ROAS are exactly the same calculation: total revenue ÷ total ad spend. «MER» became the common term after the iOS 14 attribution break because it stresses independence from tracking; «blended ROAS» is the more descriptive name. Anyone searching for either means the same metric.
How do you calculate MER, or blended ROAS?: MER = total revenue ÷ total ad spend. For example: $20,000 of revenue ÷ $8,000 of ad spend = an MER of 2.5x, or 250 %.
What is a good MER?: An MER of 3–5x is solid for most industries and margins. With high production costs or thin margins it should be closer to 5–8x. Expect the MER to sit below any channel ROAS, because it counts every marketing cost rather than one platform's.