CPM Calculator
Calculate CPM, or solve for cost or impressions, from the other two — with the formula shown, not just a number.
CPM (cost per mille/thousand) is what you pay for every 1,000 ad impressions. It measures cost efficiency of reach, not performance — a lower CPM does not automatically mean a better campaign if those impressions convert poorly; pair it with CTR and conversion metrics for the full picture.
Calculated entirely in your browser — nothing you enter here is sent to a server.
CPM stands for cost per mille — mille being Latin for thousand — so CPM is simply what you're paying for every 1,000 ad impressions. It's a reach-efficiency metric, not a performance metric: a campaign with a low CPM but a poor click-through or conversion rate can still be a worse investment than one with a higher CPM that actually drives results.
Use "Solve for cost" or "Solve for impressions" when you already know a platform's stated CPM and want to work out what a given budget will actually buy, or how much budget you need for a target number of impressions.
How to use the CPM Calculator
- Under "What do you want to calculate?", choose Solve for CPM, Solve for cost, or Solve for impressions.
- Fill in the two fields shown for that mode, for example Cost ($) and Impressions.
- Click Calculate to see the result with the CPM formula under it.
- Click Reset to clear both fields before a new calculation.
Example: From a campaign report to a budget plan
Solve for CPM with Cost ($) 250 and Impressions 40000 returns $6.25. Then switch to Solve for impressions and enter CPM ($) 6.25 and Cost ($) 1000: the tool returns 160,000 impressions for that budget.
Questions about the CPM Calculator
- Why does Solve for impressions show a whole number?
- Impressions are whole events, so the result is the number of impressions the budget fully pays for, rounded down. CPM 7 with Cost 100 shows 14,285, with a note that the exact result is 14,285.71.
- Why do I get "Impressions must be a whole number"?
- Impressions are counted events, so Solve for CPM and Solve for cost reject fractional impression counts such as 40000.5. Cost and CPM may have decimals.
- Can I solve for impressions with a CPM of zero?
- No. CPM must be greater than zero in that mode, and in Solve for CPM the impressions cannot be zero, because both cases would divide by zero. Negative values are rejected in every mode.
- Does the $ sign mean it only works in US dollars?
- The label shows $, but the math is unit-free. Enter costs in any one currency and the cost or CPM result is in that same currency.
- How are costs rounded?
- Money is shown with two decimals, so 260 ÷ 40,000 × 1,000 displays as $6.50. Amounts under one cent keep up to four decimals instead of showing $0.00.