CPM calculator with CPC, CTR and CPA: every ad metric from the numbers you have
CPM is spend ÷ impressions × 1,000. CTR is clicks ÷ impressions. CPC is spend ÷ clicks, and CPA is spend ÷ conversions. Example: €3,000 for 250,000 impressions is a €12 CPM; at a 1% CTR that is a €1.20 CPC, and at an 8% conversion rate a €15 CPA. The free calculator fills in every metric from the numbers you have and shows what moved your CPA.
Open the free CPM, CPC, CTR and CPA calculator ↓
On this page11 sections
CPM, CPC, CTR and CPA calculator
CPM, CPC, CTR and CPA calculator
1. Enter what you know — the rest is filled in
Green boxes are calculated from your numbers; grey ones are what you entered.
2. What does a target CPA need?
3. Compare two periods: what moved CPA?
| Period | Spend | Impressions | Clicks | Conversions |
|---|---|---|---|---|
| Before | ||||
| After |
Everything is calculated in your browser. Fill in any numbers you have; the tool applies the formulas below until nothing more follows, and warns you when two of your numbers contradict each other — usually a sign that clicks or conversions came from different columns.
How do you calculate CPM, CPC, CTR and CPA?
| Formula | Example | |
|---|---|---|
| CPM (cost per mille) | spend ÷ impressions × 1,000 | €3,000 ÷ 250,000 × 1,000 = €12 |
| CTR (click-through rate) | clicks ÷ impressions × 100% | 2,500 ÷ 250,000 = 1% |
| CPC (cost per click) | spend ÷ clicks = CPM ÷ (1,000 × CTR) | €12 ÷ (1,000 × 0.01) = €1.20 |
| Conversion rate | conversions ÷ clicks × 100% | 200 ÷ 2,500 = 8% |
| CPA (cost per acquisition) | spend ÷ conversions = CPC ÷ conversion rate | €1.20 ÷ 0.08 = €15 |
| ROAS | revenue ÷ spend | €9,000 ÷ €3,000 = 3× |
CPM measures the amount spent on an ad campaign, divided by impressions, multiplied by 1,000.
Google defines average CPC as “the total cost of your clicks” divided by “the total number of clicks” (Google) and CTR as clicks ÷ impressions (Google). When you add up several campaigns, add the amounts first and divide once; averaging the CPMs of campaigns of different sizes gives the wrong answer.
PPC budget calculator: what will your budget buy?
They form one chain: budget buys impressions at the CPM, a share of impressions become clicks (CTR), and a share of clicks become conversions. Type a budget into Spend above with your CPM, CTR and conversion rate, and the calculator shows what it buys.
impressions = budget ÷ CPM × 1,000 clicks = impressions × CTR conversions = clicks × conversion rate CPA = CPM ÷ (1,000 × CTR × conversion rate)
At €3,000, a €12 CPM, 1% CTR and 8% conversion rate: 250,000 impressions, 2,500 clicks, 200 conversions, €15 each. Doubling the CTR halves the CPA just as surely as halving the CPM does.
Why three rates are not enough
Three rates — say CPM, CTR and conversion rate — give you every other rate, including CPC and CPA, but not how many impressions or conversions you will get. For volumes you need one amount: a budget, impressions, clicks or conversions. And some sets add nothing: CPM, CTR and CPC are linked, so the third always follows from the other two.
What CTR do you need to hit a target CPA?
Turn the chain around:
CTR needed = CPM ÷ (1,000 × conversion rate × target CPA) conversion rate needed = CPM ÷ (1,000 × CTR × target CPA) highest CPM you can pay = 1,000 × CTR × conversion rate × target CPA
With a €12 CPM, an 8% conversion rate and a €25 target you need a CTR of at least 0.60%. If your ads run at 0.4%, the target is out of reach until the creative, the landing page or the price of impressions changes. What CPA you can afford in the first place comes from your margin and close rate — that is our break-even ROAS and CPA calculator.
Why did my CPA go up: CPM, CTR or conversion rate?
Because CPA = CPM ÷ (1,000 × CTR × conversion rate), the change in CPA between two periods splits exactly into three parts, measured in logarithms so that they add up:
ln(CPA₂ ÷ CPA₁) = ln(CPM₂ ÷ CPM₁) − ln(CTR₂ ÷ CTR₁) − ln(CR₂ ÷ CR₁)
Example
Before: €2,000, 160,000 impressions, 1,600 clicks, 80 conversions — CPM €12.50, CTR 1.00%, conversion rate 5%, CPA €25. After: €2,400, 160,000 impressions, 1,440 clicks, 72 conversions — CPM €15 (+20%), CTR 0.90% (−10%), conversion rate unchanged, CPA €33.33 (+33%). About 63% of the rise comes from CPM and 37% from CTR. Look at the auction and audience first, then the creative.
This shows where the cost moved, not why. CPM and CTR are linked: the delivery system may buy more expensive impressions when they convert better, and a tired creative can raise CPM through lower ad quality.
Do Meta, Google, LinkedIn and TikTok calculate these metrics the same way?
The names match; the denominators do not. Use clicks and conversions from columns that belong together, or CPC ÷ conversion rate will not equal the CPA in your report.
| Clicks in CTR and CPC | Conversion rate is per | Watch out for | |
|---|---|---|---|
| Meta | CTR (all) counts any click; link CTR only clicks to your destination | No single column; results follow the objective | Opening an Instant Form counts as a link click |
| Google Ads | Clicks | Interaction (Google) | Conversions are booked on the click date (Google) |
| Chargeable clicks for your objective (LinkedIn) | Click (LinkedIn) | Conversions include actions after a view, so the rate can exceed 100% | |
| Microsoft Advertising | Clicks | Click (Microsoft) | In the Reporting API, use ConversionsQualified; the old Conversions column is deprecated |
| TikTok | Clicks (all) include social interactions; Clicks (destination) do not | Impression by default; “CVR (clicks)” is per click (TikTok) | Its basic metrics page lists cost per 1,000 people reached, not CPM |
Google also sells viewable CPM on the Display Network: you pay only for impressions where at least half the ad is on screen for a second, or two seconds of video (Google). vCPM is therefore never lower than CPM for the same ads.
What is a good CPM, CTR or CPC?
There is no reliable universal number, and published averages disagree more than industries do:
| Figure | Source and sample | |
|---|---|---|
| Search CTR, all industries | 6.64% for 2026 | LocaliQ, its customers’ Google and Microsoft campaigns (vendor) |
| Search CPC, all industries | $5.42 for 2026 | Same source |
| Facebook CPM, median | $7.26 | Databox, over 2,800 companies (vendor) |
| Facebook CPM | $20.59 | Superads, accounts using its tool, called both a median and a mean on the same page (vendor) |
| TikTok CPM, median | $4.08 | Focus Digital, August 2025 – July 2026, combined datasets (vendor) |
Two vendors’ Facebook CPMs differ almost threefold, and “a good CTR is 1.9%” still circulates without a source or a year. Use outside figures as an order of magnitude; compare with your own previous period (part 3 of the calculator) and with the CPA you can afford. More on each metric: Facebook CPM, Facebook CTR.
Is this CPM the same as YouTube CPM?
No. This calculator is for advertisers: CPM is what you pay per 1,000 ad impressions. YouTube creators also see CPM, plus RPM — what they earn per 1,000 views after YouTube’s share. And in project management, CPM means the critical path method, which has nothing to do with ads.
How does Variafy use these metrics?
Variafy reads spend, impressions, clicks and conversions from Meta, Google Ads, LinkedIn and Microsoft ad accounts in ChatGPT or Claude, so you can ask “compare last week with the week before and tell me whether CPM, CTR or conversion rate moved CPA” instead of exporting reports. The chain does not stop at a lead: Variafy matches spend with payments in your CRM, so the last step is the cost of a paying customer — see connecting Facebook ads to CRM sales.
How we checked
Checked on 23 Oct 2026 against Google Ads Help (average CPC, CTR, CPM and viewable CPM, conversion rate, conversion columns), the Google Ads API metrics reference, TikTok’s basic metrics, LinkedIn’s performance and conversion metrics, and Microsoft Advertising’s report column reference; Meta’s definitions are those we checked for our Facebook CPM and CTR guides. Benchmarks are quoted from the vendors that publish them, with their sample; we do not endorse any of them.
The CPA split between periods is an identity — it always adds up — not a causal model. We tried the calculators we found through web search; none split a change in CPA into CPM, CTR and conversion rate.
Questions
How do you calculate CPM?
Spend ÷ impressions × 1,000. €50 for 10,000 impressions is a €5 CPM. It counts impressions, not people: the cost per 1,000 people reached is a different metric.
How do you calculate CTR?
Clicks ÷ impressions × 100. Check which clicks: Meta’s CTR (all) counts any click and link CTR only clicks to your site; LinkedIn counts chargeable clicks only.
How do you calculate CPC from CPM and CTR?
CPC = CPM ÷ (1,000 × CTR). A €12 CPM at a 1% CTR is a €1.20 CPC. Use the same kind of click for both numbers.
How do you calculate CPA?
Spend ÷ conversions, or CPC ÷ conversion rate. A €1.20 CPC at an 8% conversion rate is a €15 CPA.
What CTR do I need to hit my target CPA?
CTR = CPM ÷ (1,000 × conversion rate × target CPA). At a €12 CPM, 8% conversion rate and €25 target, you need at least 0.60%.
My CPA went up. Is it CPM, CTR or conversion rate?
Compare two periods: the change in CPA splits exactly into the changes in CPM, CTR and conversion rate. The biggest share is where to look first; it shows where the cost moved, not why.
What is a good CPM, CTR or CPC?
There is no universal number; published averages for the same platform differ almost threefold between sources. Compare with your own previous periods and with the CPA your margin allows.
What is vCPM in Google Ads?
The cost per 1,000 viewable impressions: a display ad counts when half of it is on screen for at least a second, a video after two seconds of play. vCPM is never lower than CPM.
Why does conversion rate × clicks not match conversions in my report?
Denominators differ: Google divides by interactions, Microsoft by clicks, TikTok’s default CVR by impressions, and view-through conversions have no click at all.