CPA CALCULATOR

Use our FREE CPA calculator to work out your cost per acquisition

CPA calculator

Knowing your Cost Per Acquisition (CPA) is essential for effective marketing planning.

It helps you understand exactly how much you’re spending to acquire a customer, whether through paid ads, social media campaigns or other marketing efforts. With this insight, you can fine-tune your campaigns, optimise your budget, and focus on the strategies that deliver the best results.

Using our CPA calculator

Our easy-to-use CPA calculator takes the guesswork out of the equation, giving you accurate and actionable insights in seconds.

Not only that, but you’ll find FAQs and a handy guide on this page to help you better understand CPA and how it supports everything from improving ROI to building more efficient lead-generation funnels.

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The total budget spent on the campaign or marketing activity.
The total number of leads generated from the campaign (but have not converted into sales).
The total number of successful conversions from leads, such as sales made.
The total revenue generated from the campaign.

CPA calculator results

How much it costs to generate a lead from your ad spend investment.
Actual cost for each acquisition from your ad campaign.
The actual amount in revenue that you will make on your advertising investment
The percentage return you will make on your ad spend investment.

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How to use the CPA calculator – step-by-step guide

This guide walks you through how to use our calculator, explaining what each input field means, why it matters and giving examples to help you make the most of it.

Fill in the input fields

These are the numbers you’ll need to provide for accurate calculations:

1. Total ad spend (£)

What it means: The total amount of money you’ve spent on your marketing campaign. This includes all costs, such as PPC ads, social media ads and SEO spend.

Why it matters: Ad spend is the foundation of all the calculations – it tells us how much you’re investing to acquire leads and customers.

Example: If you’ve spent £2,500 on a Google Ads campaign, enter “2500” in this field.

2. Number of leads

What it means: The total number of leads generated from the campaign. A lead is a potential customer who has shown interest in your business such as filling in a form, signing up for a newsletter and so on.

Why it matters: This figure helps us calculate your Cost Per Lead (CPL), which shows how much you’re spending to generate interest in your brand.

Example: If 400 people signed up for your free guide as part of a campaign, enter “400” here.

3. Number of acquisitions

What it means: The total number of successful conversions from your campaign. A conversion could be a sale, sign-up, download or any action you’ve defined as valuable.

Why it matters: Knowing how many acquisitions you’ve made allows us to calculate how much each one cost you (CPA).

Example: If your campaign resulted in 100 product purchases, enter “100” here.

4. Revenue (£)

What it means: The total income you earned from your campaign. This is the gross revenue generated directly by the customers acquired through the campaign.

Why it matters: Revenue is essential for calculating your Return on Investment (ROI). It shows whether your campaign is profitable or not.

Example: If the customers acquired through your campaign brought in £8,000 in sales, enter “8000” here.

Understanding the results from the CPA calculator

Once you’ve entered the inputs, the calculator will display these results:

1. Cost Per Lead (CPL) (£)

What it means: How much you’re spending to generate a single lead.

Why it matters: CPL gives insight into the top of the funnel and whether your campaign is effectively generating interest.

Example: If you spent £2,500 and acquired 400 leads, your CPL is £6.25.

2. Cost Per Acquisition (CPA) (£)

What it means: How much each successful conversion, such as a sale, cost you.

Why it matters: CPA helps you understand whether your marketing spend is efficient and aligns with your goals.

Example: If you spent £2,500 and gained 100 customers, your CPA will be £25.

3. Return on Investment (ROI) (£)

What it means: The net profit (or loss) from your campaign after deducting ad spend.

Why it matters: ROI shows whether your campaign was worth the investment in real monetary terms.

Example: If you earned £8,000 in revenue and spent £2,500, your ROI is £5,500.

4. Return on Investment (ROI) (%)

What it means: The percentage profit (or loss) relative to your ad spend.

Why it matters: ROI percentage helps you evaluate the campaign’s efficiency and compare it to other campaigns.

Example: With £8,000 revenue and £2,500 spend, your ROI is 220%.

Interpret your CPA calculation results

Use these insights to optimise your marketing campaigns:

  • High CPA or CPL – Consider improving targeting or adjusting your ad creatives to drive down costs.
  • Low ROI (£ or %) – Re-evaluate your campaign strategy, focus on higher-converting channels, or reduce ad spend.
  • Healthy ROI and CPA – Excellent! Use the data as a benchmark for future campaigns.

Search Engine Optimisation (SEO) FAQs

Conversion rate is the percentage of users who take a desired action out of the total number of users who interacted with your campaign, website or landing page.

This action could be making a purchase, signing up for a newsletter, downloading a resource or completing a form.

Conversion rate is an essential metric because it helps measure how effectively your marketing and website are driving user actions.

Conversion rate tells you how efficiently your campaigns and website are turning visitors into customers or leads.

A higher conversion rate means more revenue without increasing traffic or spend.

Key benefits of monitoring conversion rate:

  • Improves ROI – Identifies which campaigns or pages are the most effective.
  • Optimises budget – Allows you to allocate resources to high-performing strategies.
  • Enhances user experience – Conversion rate improvements often go hand-in-hand with better website usability.

For more insights on conversion rates and their importance, check out HubSpot’s guide to conversion optimisation.

To calculate your conversion rate, follow these steps:

  1. Determine the number of conversions (eg, purchases or form submissions).
  2. Divide the total conversions by the total number of visitors or interactions.
  3. Multiply by 100 to get the percentage.

For ecommerce websites, tools like Google Analytics can calculate your conversion rate automatically.

A “good” conversion rate varies by industry and type of campaign. However, the average conversion rate across industries is typically between 2-5% for most websites.

Here’s a rough breakdown:

  • Ecommerce sites – 1-3% (though top-performing sites achieve over 10%).
  • Lead generation – 2-5%.
  • Landing pages – 10-20% when optimised.

Several factors influence how well your visitors convert:

  • Page speed – A slow-loading website drives visitors away. Aim for load times under 3 seconds (check speeds with Google PageSpeed Insights).
  • User experience (UX) – A confusing layout or poorly designed navigation reduces conversions.
  • Call-to-Action (CTA) – Weak or unclear CTAs can lead to missed opportunities.
  • Relevance of content – Ensure the offer aligns with visitor intent.
  • Trust signals – Customer reviews, testimonials and secure payment icons boost credibility.

Improving these areas often leads to a noticeable increase in conversion rates.

To boost your conversion rate, focus on strategies that enhance the user experience and provide value to your audience:

  • A/B testing – Test different versions of your landing pages, CTAs or ads to see what performs better.
  • Optimise CTAs – Use action-driven language and place CTAs prominently.
  • Simplify forms – Reduce the number of fields in your forms to make them quick and easy to complete.
  • Use social proof – Highlight customer testimonials, reviews or case studies.
  • Targeted messaging – Personalise your offers based on audience demographics or behaviour.