Bing Ads ROI Calculator

The maths behind it

The calculation is identical to Google Ads: ROI = (revenue × contribution margin − spend) ÷ spend, with ROAS = revenue ÷ spend.

What differs is the input economics. Microsoft Advertising typically delivers lower cost per click and lower volume than Google, with an audience skewing older and more desktop-based.

Lower CPCs at a similar conversion rate produce a better cost per acquisition, which is the channel's central argument.

Putting numbers to it

The same campaign run on both platforms: Google at a $0.95 CPC and 3.5% conversion gives a $27.14 CPA. Microsoft at a $0.62 CPC and 3.6% conversion gives $17.22.

Against $31.90 of contribution, Google leaves $4.76 per order and Microsoft leaves $14.68, three times the profit per customer.

The catch is volume: the same campaign might produce 1,300 conversions a month on Google and 180 on Microsoft.

Total contribution is $6,188 against $2,642, so Google generates more money and Microsoft generates it more efficiently. Both are worth running and neither substitutes for the other.

Where it is unreliable

The efficiency advantage is real and the volume ceiling is low, so a business planning to move budget from one to the other will find the second cannot absorb it.

Audience differences also mean performance does not transfer directly. A campaign that works on one platform may perform quite differently on the other, particularly in categories with a strong age or device skew.

How to act on this

Run it as an incremental channel rather than an alternative, importing the Google campaign structure as a starting point and then letting the two diverge as the data justifies.

Then judge it on total contribution rather than on efficiency alone. A channel with a superb cost per acquisition and trivial volume is worth having and is not a strategy.

Why the cheaper channel stays cheaper

Cost per click is set by competitive density, and fewer advertisers compete on the smaller platform. That gap persists because the volume ceiling deters advertisers who need scale, which keeps the auction less contested.

It is therefore a durable inefficiency rather than a temporary one, and it rewards advertisers willing to run a second account for a fraction of their total volume.

The setup cost is low, campaign import takes minutes, and the ongoing management is proportional to the spend. For most accounts already running search, it is close to free money, and the most common reason it goes unclaimed is simply that nobody has got round to it.

On top of that, importing a Google campaign brings across structure but not necessarily the right bids, because click prices and conversion rates differ. An imported campaign left on Google's bids will usually overbid substantially.

Reviewing bids against the new platform's own break-even after a few weeks of data is what turns an import into a working account rather than a duplicate.

Auto-import settings should also be checked, since an ongoing sync will overwrite platform-specific bid work with the Google values.

Microsoft Advertising is worth calculating separately rather than assuming it mirrors Google, because the audience differs. Search volume is a fraction of Google's, and cost per click is frequently 30% to 50% lower, with a demographic skewing older and more desktop-based. Those two facts together mean the return on a smaller budget is often better, which is the argument for running it at all.