CALCULATE THE COST OF ONE AD IMPRESSION
Cost per impression is a tiny number, so it is easy to misread. This calculator keeps the unit conversion visible: spend divided by impressions, with CPM as the same result scaled to 1,000 views.
Enter your ad spend and total impressions to calculate cost per 1,000 impressions.
$5.00 for every 1,000 impressions.
$500.00 ÷ 100,000 × 1,000THE QUICK ANSWER
Cost per impression = ad spend ÷ total impressions. CPM = cost per impression × 1,000.
For example, $500 divided by 100,000 impressions equals $0.005 per impression. Multiply $0.005 by 1,000 to get a $5.00 CPM.
Use the same campaign scope for both inputs: divide media spend by delivered impressions. If spend is $500 and impressions are 100,000, the calculation is $500 ÷ 100,000 = $0.005. This metric is often easier to read as CPM because an individual impression cost is usually a fraction of a cent.
Cost per impression and CPM describe the same delivery cost at different scales. CPI is the cost of one impression. CPM is the cost of 1,000 impressions. Multiply CPI by 1,000 to find CPM, or divide CPM by 1,000 to find CPI. Do not compare one page’s CPI with another page’s CPM without converting the units first.
Use CPI when reviewing a detailed media plan, checking an invoice, or explaining the price of individual delivery. For campaign decisions, pair it with reach, frequency, click-through rate, cost per click and cost per acquisition. An inexpensive impression is useful only if it supports the campaign objective.
The most common error is mixing reach with impressions. Reach counts unique people, while impressions include repeat views. Another error is mixing all-in campaign cost with platform-reported media spend. Keep the cost definition consistent and document whether agency fees, production costs and taxes are included.
Compare CPI or CPM against comparable placements and audiences, then inspect frequency and downstream results. If frequency is high but reach is flat, more impressions may not create proportional new awareness. Use the Impressions Calculator to turn a budget and CPM assumption into a delivery estimate, or the Reverse CPM Calculator to set a planning ceiling.
NEXT, COMPARE THE NUMBERS
CPM only explains the cost of delivery. Read CPM vs CPC vs CPA to choose the metric that matches your objective, or use the cost per impression calculator to view the same delivery cost at an individual-impression scale.
Cost per impression is the media cost assigned to one delivered ad impression. Calculate it by dividing ad spend by total impressions.
Divide CPM by 1,000. For example, a $5 CPM equals $0.005 per impression.
No. Impressions include repeat views, while reach estimates unique people. You need a frequency assumption to relate impressions to reach.