CPM and CPC Calculator
Calculate CPM, CPC, CTR, CPA and ROAS from your ad spend, impressions and clicks, or work out what a CPM budget will buy. Free and instant.
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Reverse: what will a CPM budget buy?
About the CPM and CPC Calculator
This CPM calculator turns your campaign numbers into the metrics advertisers use every day: CPM (cost per 1,000 impressions), CPC (cost per click), CTR (click-through rate), and, if you add conversions and revenue, CPA (cost per acquisition), conversion rate and ROAS (return on ad spend). A second block works in reverse: enter a CPM and a budget to see how many impressions and clicks you can expect.
Use it for Google Ads, Meta, TikTok, YouTube, programmatic and display campaigns, or to price ad space on your own site. For return on any investment see the ROI calculator, and to measure campaign return see the ROAS calculator.
How to use it
- Enter your total ad spend and the impressions delivered.
- Add the number of clicks, and optionally conversions and revenue.
- Press Calculate to see CPM, CPC, CTR, CPA, conversion rate and ROAS.
- Use the reverse block to plan how many impressions and clicks a budget can buy.
Formulas
| Metric | Formula |
|---|---|
| CPM | ad spend ÷ impressions × 1,000 |
| CPC | ad spend ÷ clicks |
| CTR | clicks ÷ impressions × 100 |
| CPA | ad spend ÷ conversions |
| Conversion rate | conversions ÷ clicks × 100 |
| ROAS | revenue ÷ ad spend |
Example: $500 spent for 100,000 impressions is a CPM of $5.00. With 1,200 clicks the CPC is $0.42 and the CTR is 1.2 %.
CPM vs CPC: which should you pay for?
- CPM (pay per 1,000 views) suits brand awareness and large reach. You pay whether or not people click.
- CPC (pay per click) suits traffic and lead generation, because you pay only when someone visits.
- The two are linked by CTR: CPC = CPM ÷ (CTR × 10). A higher CTR lowers your effective CPC at the same CPM.
How to lower your CPM and CPC
- Improve ad relevance and creative so CTR rises.
- Narrow audiences to people likely to convert instead of the broadest reach.
- Test placements and time of day; costs vary a lot by season (Q4 is usually the most expensive).
- Fix the landing page: a better conversion rate lowers CPA even when CPC stays the same.
Frequently asked questions
How do you calculate CPM?
CPM = (total ad spend ÷ impressions) × 1,000. If you pay $500 for 100,000 impressions, CPM is $5.
What is a good CPM?
It depends on platform, audience, country and season. Compare your CPM with your own history and with similar campaigns rather than a single universal number.
What is the difference between CPM and CPC?
CPM is the cost per 1,000 ad views. CPC is the cost of each click. You can convert between them with CTR: CPC = CPM ÷ (CTR × 10) when CTR is a percentage.
How do I calculate CTR?
CTR = clicks ÷ impressions × 100. 1,200 clicks on 100,000 impressions is a 1.2 % CTR.
What is ROAS and how is it different from ROI?
ROAS is revenue divided by ad spend, so $1,800 revenue on $500 spend is 3.6x. ROI also subtracts product and operating costs, so it measures real profit.
Can I use this CPM calculator for my own website ads?
Yes. Enter your ad revenue as the cost and your page views as impressions to see your effective RPM, the same math publishers use.
Last reviewed: November 2026.
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