CPM Calculator (Cost Per Mille)
Calculate cost per thousand impressions, convert between CPM and total spend, and derive effective CPM from clicks and conversions.
📣 Marketing📐 CPM = (total spend / impressions) × 1000💼 Business
Total ad spend
Impressions delivered
Clicks (optional)
Conversions (optional)
Please enter valid values.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| CPM Calculator (Cost Per Mille) | — | CPM = (total spend / impressions) × 1000 | currency per 1,000 |
Step-by-Step Examples
Example 1
Display Campaign
Spend 4,500, impressions 900,000, clicks 7,200, conversions 180.
- CPM = (4,500 / 900,000) × 1,000 = 5.00
- CTR = 7,200 / 900,000 = 0.80%
- CPC = 4,500 / 7,200 = 0.63
- CPA = 4,500 / 180 = 25.00
✓ CPM 5.00, CPC 0.63, CPA 25.00
Example 2
Premium Placement
Spend 12,000, impressions 400,000.
- CPM = (12,000 / 400,000) × 1,000
- CPM = 30.00
- High CPM typical of targeted or premium inventory
✓ CPM 30.00
Example 3
Broad Reach
Spend 800, impressions 1,600,000.
- CPM = (800 / 1,600,000) × 1,000
- CPM = 0.50
- Very low CPM, typical of broad untargeted inventory
✓ CPM 0.50
Real-World Applications
Media Buying
CPM is the standard pricing unit for display, video, and programmatic inventory, making it the basis of most media negotiations.
Brand Campaigns
For awareness objectives where clicks are not the goal, CPM is the primary efficiency measure.
Placement Comparison
Comparing CPM across placements reveals what audience targeting and inventory quality actually cost.
Metric Bridge
CPM combined with CTR and conversion rate connects impression-level cost to acquisition cost.
Common Mistakes to Avoid
⚠️
Comparing CPM across different audiences
A 30 CPM for a tightly targeted high-value audience can outperform a 2 CPM for untargeted reach. CPM alone says nothing about audience quality.
⚠️
Optimising for low CPM
Cheap impressions are easy to buy and frequently worthless. Downstream metrics — CPA and ROAS — are what determine whether the spend worked.
⚠️
Ignoring viewability and fraud
Served impressions are not necessarily seen impressions. Effective CPM on viewable, human impressions can be far higher than the headline figure.
Frequently Asked Questions
What is CPM? ▾
Cost per mille, meaning cost per thousand impressions — total spend divided by impressions, multiplied by a thousand.
What is a good CPM? ▾
It varies enormously by channel, format, and targeting. Broad display can run under 2 while narrowly targeted video or premium placements can exceed 40.
How does CPM relate to CPC? ▾
CPC equals CPM divided by ten times the click-through rate percentage. A 5 CPM at 1% CTR gives a 0.50 CPC.
When should I optimise for CPM instead of CPA? ▾
For awareness and reach objectives where the goal is exposure rather than immediate response. For direct response, CPA and ROAS matter far more.
What is viewable CPM? ▾
CPM calculated only on impressions that actually entered the viewport for a minimum duration — usually meaningfully higher than served CPM.