Key takeaway
CPM prices impressions, CPC prices clicks, CPA prices acquisitions. Match model to objective.
Translations need honest CTR and conversion rates.
What it means
Definitions: CPM, CPC, CPA.
Awareness leans CPM; performance leans CPC/CPA; revenue adds ROAS.
Billing model may differ from reporting KPI.
When you would use it
Pick language that matches the contract and the funnel stage.
Use all three to explain broken funnels.
How to use the tool
Use the matching TCB Tools page and work top to bottom:
- Open CPM, CPC and ROAS calculators.
- Use one campaign export.
- Compute each metric.
- Note which number is contractual.
No account is required. Results update as you type.
How the models relate + worked example
Approx CPC ≈ CPM/(10×CTR%) when CTR is percent — verify with raw totals.
$10 CPM at 1% CTR ≈ $1 CPC before ledger checks.
CPA = spend ÷ conversions; $1000÷50=$20.
How to read the result
Best model aligns to measurable outcomes.
Do not crown CPM wins if you sell products and ignore CPA.
Estimates only.
Common mistakes
- Raw CPM across unlike placements. Group formats.
- Cheap CPC celebration. Check conversion.
- CPA without attribution notes. Document.
- Mixing billed vs observed. Label.
- One KPI for every stage. Stage metrics.
Related ideas
Ask which number is contractual in agency decks.
View-through can flatter CPA.
If you are new, read once for the story, then again for the clicks you will make.
Write inputs down before changing live budgets or deleting files — calm beats guesswork.
Note the date range, currency or filename so teammates can reproduce the result.
Interactive math and many file jobs run in your browser here; treat outputs as planning aids, not certified professional advice.
When a result looks too good, recheck definitions: units, filters and windows hide surprises.
Practice with example numbers first, then replace them with trusted exports.
Small disagreements between systems are often rounding or filters — investigate before panicking.
Consistent naming, windows and currencies beat clever one-off spreadsheets.
Operators who revisit buying models weekly catch drift earlier than teams who only look after emergencies.
Teach one teammate how you measure buying models; shared definitions prevent quiet disagreement.
Bookmark the guide and the tool together so beginners always have both the why and the workspace.
When unsure about buying models, reduce scope: one campaign, one file, one list — prove the method, then scale.
Screenshots of inputs beside outputs speed audits when someone questions buying models.
If leadership wants only a headline, still keep working notes for buying models in your own folder.
Seasonality and promotions change buying models; annotate the calendar when comparing periods.
Automation helps, but a human still owns success criteria for buying models.
Revisit assumptions about buying models after tool, tracking or pricing changes.
A short checklist for buying models beats relying on memory during busy weeks.
Ask which number is contractual in agency decks.
View-through can flatter CPA.
If you are new, read once for the story, then again for the clicks you will make.
Write inputs down before changing live budgets or deleting files — calm beats guesswork.
Note the date range, currency or filename so teammates can reproduce the result.
Interactive math and many file jobs run in your browser here; treat outputs as planning aids, not certified professional advice.
When a result looks too good, recheck definitions: units, filters and windows hide surprises.
Practice with example numbers first, then replace them with trusted exports.
Small disagreements between systems are often rounding or filters — investigate before panicking.
Consistent naming, windows and currencies beat clever one-off spreadsheets.
Operators who revisit buying models weekly catch drift earlier than teams who only look after emergencies.
Teach one teammate how you measure buying models; shared definitions prevent quiet disagreement.
Bookmark the guide and the tool together so beginners always have both the why and the workspace.
When unsure about buying models, reduce scope: one campaign, one file, one list — prove the method, then scale.
Screenshots of inputs beside outputs speed audits when someone questions buying models.
If leadership wants only a headline, still keep working notes for buying models in your own folder.
Seasonality and promotions change buying models; annotate the calendar when comparing periods.
Automation helps, but a human still owns success criteria for buying models.
Revisit assumptions about buying models after tool, tracking or pricing changes.
A short checklist for buying models beats relying on memory during busy weeks.
Ask which number is contractual in agency decks.
View-through can flatter CPA.
If you are new, read once for the story, then again for the clicks you will make.
Write inputs down before changing live budgets or deleting files — calm beats guesswork.
Note the date range, currency or filename so teammates can reproduce the result.
Interactive math and many file jobs run in your browser here; treat outputs as planning aids, not certified professional advice.
When a result looks too good, recheck definitions: units, filters and windows hide surprises.
Practice with example numbers first, then replace them with trusted exports.
Small disagreements between systems are often rounding or filters — investigate before panicking.
Consistent naming, windows and currencies beat clever one-off spreadsheets.
Operators who revisit buying models weekly catch drift earlier than teams who only look after emergencies.
Teach one teammate how you measure buying models; shared definitions prevent quiet disagreement.
Bookmark the guide and the tool together so beginners always have both the why and the workspace.
When unsure about buying models, reduce scope: one campaign, one file, one list — prove the method, then scale.
Screenshots of inputs beside outputs speed audits when someone questions buying models.
If leadership wants only a headline, still keep working notes for buying models in your own folder.
Seasonality and promotions change buying models; annotate the calendar when comparing periods.
Automation helps, but a human still owns success criteria for buying models.
Revisit assumptions about buying models after tool, tracking or pricing changes.
A short checklist for buying models beats relying on memory during busy weeks.
Ask which number is contractual in agency decks.
View-through can flatter CPA.
If you are new, read once for the story, then again for the clicks you will make.
Try the tools
Open those three tools with one shared campaign story.
