BYTETOOLS

CPM Calculator

Solve for CPM, impressions or ad spend, then add clicks and conversions to get CTR, CPC, conversion rate and cost per conversion. Free and offline.

$2.00
CPM
250,000
Impressions
$500.00
Total cost

Optional: add clicks and conversions

0.50%
CTR
$0.40
CPC
3.20%
Conversion rate
$12.50
Cost per conversion

Compare a CPC deal against a CPM deal

A cost-per-click price is only comparable to a CPM price once you assume a click-through rate. Enter both and this shows the effective CPM you would be paying.

$10.00
Effective CPM (eCPM)
20.0
Clicks per 1,000 impressions

CPM = cost ÷ impressions × 1,000  ·  impressions = cost ÷ CPM × 1,000  ·  eCPM = CPC × CTR% × 10

Worked example: $500.00 buying 250,000 impressions is a $2.00 CPM. If that campaign returns a 0.5% CTR you get 1,250 clicks, so the CPC is $0.40. Going the other way, a $0.50 CPC at a 2% CTR is the same as paying a $10.00 CPM.

CPM stands for cost per mille — the price of a thousand ad impressions, not a thousand people. Enter net cost if your platform reports media spend separately from agency or ad-serving fees, otherwise the CPM you calculate will be lower than the one you actually pay. All figures are typed by you and calculated in your browser; nothing is uploaded.

What is the CPM Calculator?

The ByteTools CPM Calculator works out cost per thousand impressions in whichever direction you need it.

  • Solves for CPM, impressions or spend from the other two
  • CTR, CPC, conversion rate and cost per conversion
  • Effective CPM from a CPC price and an assumed click-through rate
  • Clicks per thousand impressions at any CTR
  • Seven currency symbols
  • Pure arithmetic in your browser — no ad platform connection

How to use the CPM Calculator

  1. 1

    Choose whether to solve for CPM, impressions or total campaign cost.

  2. 2

    Enter the two figures you already know.

  3. 3

    Read the completed CPM, impressions and cost triplet.

  4. 4

    Optionally add clicks and conversions for CTR, CPC and cost per conversion.

  5. 5

    Use the CPC comparison box to convert a click price into an effective CPM.

About the CPM Calculator

The ByteTools CPM Calculator works out cost per thousand impressions in whichever direction you need it. Pick what you are solving for — CPM, impressions or total spend — and enter the two figures you already know. The formula is CPM = cost ÷ impressions × 1,000.

Add optional click and conversion counts and it also reports click-through rate, cost per click, conversion rate and cost per conversion, so a single media plan can be judged on more than its headline rate. A separate section converts a CPC price into its effective CPM at an assumed click-through rate, which is the only fair way to compare a CPC deal against a CPM deal.

Nothing is fetched from any ad platform — every number is one you type, and all the arithmetic happens in your browser, so no campaign data is uploaded or stored. There are no rate cards, industry benchmarks or live auction prices baked in either, which means the answer you get reflects your own media plan rather than somebody else's averages.

Frequently asked questions

How do you calculate CPM?

Divide the total campaign cost by the number of impressions, then multiply by 1,000. Spending $500 for 250,000 impressions gives 500 ÷ 250,000 × 1,000 = a $2.00 CPM.

What does CPM stand for?

Cost per mille — mille being Latin for thousand. It is the price of one thousand ad impressions, not one thousand people, and the same person seeing your ad three times counts as three impressions.

What is the difference between CPM and CPC?

CPM charges you for views; CPC charges you only when someone clicks. Which is cheaper depends entirely on your click-through rate, which is why this tool converts between them: a CPC deal's effective CPM is CPC × CTR% × 10.

How many impressions will my budget buy?

Divide your budget by the CPM and multiply by 1,000. A $500 budget at a $2 CPM buys 250,000 impressions. Set the tool to solve for impressions and it works this out for you.

Is a low CPM always better?

No. A cheap CPM against an untargeted audience often costs more per conversion than an expensive CPM against exactly the right people. Enter your clicks and conversions here and judge the campaign on cost per conversion rather than the headline rate.

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