CPA / CPC Calculator
Compute cost per acquisition, cost per click, click-through rate and conversion rate from a single set of inputs. Fill in what you have — outputs adjust automatically.
Inputs
Add as many as you have — outputs adapt automatically.
Required for CTR and CPM.
Required for CPA and conversion rate.
Cost per Acquisition (CPA)
From 2,000 clicks at $0.50 each, 2.5% converted into customers.
- Cost per click (CPC)
- $0.50
- Click-through rate (CTR)
- 2%
- Conversion rate
- 2.5%
- CPM
- $10.00
How it's calculated
CPC = Ad spend ÷ Clicks CTR = (Clicks ÷ Impressions) × 100% Conversion rate = (Conversions ÷ Clicks) × 100% CPA = Ad spend ÷ Conversions
CPC tells you how expensive it is to get attention. CTR tells you whether your creative and audience are well-matched. Conversion rate tells you whether your landing page and offer convert that attention. CPA is the bottom line — multiplying clicks by conversion rate gives you customers, and dividing spend by customers gives you the price you paid for each one.
Definitions
Frequently asked questions
What is CPA?+
CPA stands for Cost per Acquisition (sometimes Cost per Action). It's the ad spend required to produce one conversion — a sale, lead, signup, or whichever event you're optimising for. CPA = Total ad spend ÷ Total conversions.
What's the difference between CPA and CAC?+
They're closely related. CPA usually refers to a single channel or campaign and only includes the ad cost. CAC (Customer Acquisition Cost) is broader and typically blends all marketing and sales costs across all channels divided by new customers acquired.
What is a good CTR?+
On Meta and TikTok, a 1–2% CTR is healthy for cold traffic and 3%+ is strong. Google search ads run higher (3–8% is typical because intent is higher). LinkedIn and Display run lower (0.4–1%). Always benchmark against your own historical CTR, not the industry average.
How do I lower my CPA?+
Three levers in order of impact: (1) better creative — a stronger hook can cut CPA in half; (2) better targeting — broader audiences usually outperform narrow ones on modern algorithms; (3) better landing page — improve load speed, headline match, and remove friction at checkout.
Why is the CPA reported by Meta or TikTok different from my real CPA?+
Ad platforms attribute conversions using a tracking pixel and 7-day click / 1-day view window by default. Real-world attribution (server-side, post-purchase surveys) usually shows 10–30% fewer conversions, so your true CPA is typically 10–30% higher than the platform claims.
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