What CPM, CPC and CPA mean
These three numbers describe the cost of your advertising at different stages of the funnel. CPM is what you pay for 1,000 impressions — a measure of how expensive attention is. CPC is what each click costs. CPA is what each conversion costs — a sale, lead or sign-up. Reading them together shows where a campaign is leaking money.
The formulas
CPM = Spend ÷ Impressions × 1,000
CPC = Spend ÷ Clicks
CPA = Spend ÷ Conversions
CTR = Clicks ÷ Impressions × 100
Conversion rate = Conversions ÷ Clicks × 100
How to use it
Copy spend, impressions, clicks and conversions from Meta Ads Manager, Google Ads or TikTok Ads Manager for the same date range. Pick the platform so you can keep track when comparing. Tick the USD box if you report to a regional or international team, and type in the exchange rate you want to use.
Worked example (hypothetical numbers)
Say a campaign spends KES 30,000, earns 250,000 impressions, 2,500 clicks and 50 sales. CPM = 30,000 ÷ 250,000 × 1,000 = KES 120. CPC = 30,000 ÷ 2,500 = KES 12. CPA = 30,000 ÷ 50 = KES 600. CTR is 1% and conversion rate is 2%.
Reading the results
A high CPM usually points to a narrow or competitive audience. A low CTR suggests the creative or offer is not landing. A healthy CTR with a weak conversion rate usually means the landing page, checkout or WhatsApp follow-up needs work — not the ads. Your CPA should sit comfortably below the profit you make per sale.
Frequently asked questions
Which metric matters most?
The one closest to your business goal. For sales, CPA. For awareness, CPM and reach. CPC is a useful diagnostic in between.
Why are my CPMs different on each platform?
Each platform runs its own auction with different audiences, formats and competition, so costs vary by platform, audience, season and creative.
Does the USD toggle use a live exchange rate?
No. You enter the rate, so your report matches the rate your finance team uses.