Ecommerce CAC Calculator

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This ecommerce CAC calculator shows what it really costs you to win one new customer, and whether that customer's first order pays the cost back. Enter your marketing spend, the other costs of acquisition, the number of new customers, your average first-order value and your gross margin. It returns your customer acquisition cost, first-order gross profit and first-order profit after CAC.

Ad platforms report cost per purchase, but that figure counts repeat buyers and leaves out agency fees, UGC production and software. A fully loaded CAC gives you a number you can plan a business around.

How do you calculate CAC for an ecommerce store?

Add total marketing spend to other acquisition costs such as agency fees, creative production and tools, then divide by the number of new customers acquired in the same period. $48,000 of total acquisition cost for 800 new customers gives a CAC of $60. Compare it with first-order gross profit to see if you recover it.

Ecommerce CAC calculator

Inputs: Total marketing spend ($), Other acquisition costs (agency, creative, tools) ($), New customers acquired, Average first-order value ($), Gross margin (%). The calculator runs in your browser; nothing is stored.

How to use the CAC calculator

Use the same period for every input, ideally a full month so short-term swings even out.

Total marketing spend: paid media across Meta, TikTok, Google and any other acquisition channel.
Other acquisition costs: agency fees, creative and UGC production, influencer product seeding and acquisition tools. Leave out costs aimed at existing customers.
New customers acquired: first-time buyers only, from Shopify's customer reports. Do not use total orders.
Average first-order value: the average value of a new customer's first order, which is often lower than store-wide AOV.
Gross margin %: revenue minus product cost, as a percentage of revenue. Include shipping costs here if you want a stricter view.

The CAC formula with a worked example

CAC = (marketing spend + other acquisition costs) / new customers

First-order gross profit = average first-order value x gross margin %

First-order profit after CAC = first-order gross profit - CAC

Example: an apparel brand spent $40,000 on ads in a month and $8,000 on agency fees and creative. It acquired 800 new customers. CAC is ($40,000 + $8,000) / 800 = $60. The average first order is $75 at a 65% gross margin, so first-order gross profit is $75 x 0.65 = $48.75. First-order profit after CAC is $48.75 - $60 = -$11.25.

That brand loses $11.25 on each new customer's first purchase. Whether that is acceptable depends on how many customers come back, which is what the LTV calculator measures.

Input or output	Example value
Marketing spend	$40,000
Other acquisition costs	$8,000
New customers	800
CAC	$60.00
First-order gross profit ($75 x 65%)	$48.75
First-order profit after CAC	-$11.25

How to read the result

A positive first-order profit after CAC means you make money on day one, so you can scale spend as fast as cash flow and creative allow. A negative number is not automatically bad: many subscription, supplement and skincare brands deliberately lose money on the first order because repeat purchases pay it back. The danger is losing money on the first order without proof that customers return.

Track CAC monthly and alongside spend. CAC almost always rises as budgets grow, because the cheapest buyers are reached first. The question is whether it rises slower than the value of the customers you add. For more on what drives CAC, see /glossary/cac and our guide at /blog/how-to-lower-cac.

What to do next

Run the same customer through the LTV calculator at /tools/ltv-calculator to get an LTV:CAC ratio and payback period.
Check that your campaign ROAS is above break-even with the ROAS calculator at /roas-calculator.
If CAC keeps climbing, fresh creative is usually the fastest lever. Our Meta ads agency team at /meta-ads-agency ships 30 to 50+ new creatives a month for partner brands.

Common mistakes

CAC is one of the easiest numbers to flatter by accident. A low figure feels like good news, so few founders question how it was built. Before you use CAC to set bids or budgets, check that none of the errors below have crept into your inputs. Each one makes acquisition look cheaper or first orders look more profitable than they really are, which can lead to scaling spend on campaigns that are quietly losing money.

Dividing by total orders instead of new customers, which makes CAC look far cheaper than it is.
Counting only media spend and ignoring agency, creative and tool costs.
Using store-wide AOV when first orders are smaller, which overstates first-order profit.
Reading CAC from a single week during a sale, when discounts temporarily pull in more buyers.

Proof from real accounts

3.64x ROAS over 27 days: $146,184 on $40,124 spend, 957 orders, skincare (see the proof)
4.51x ROAS in 17 days: $52,000 on $11,586 spend, 369 orders, supplement brand (see the proof)
30 to 50+ New ad creatives a month: Produced for partner brands to keep acquisition costs in check

Frequently asked questions

What should be included in ecommerce CAC?

Include every cost spent to win new customers: paid media, agency or freelancer fees, creative and UGC production, influencer costs and acquisition software. Exclude costs aimed at existing customers, such as retention email tools. Divide the total by first-time customers only. A fully loaded CAC is higher than ad platform cost per purchase.

Why is my CAC higher than my cost per purchase in Ads Manager?

Ads Manager cost per purchase counts every purchase it attributes, including repeat customers, and only includes media spend. CAC divides all acquisition costs by new customers only. Repeat buyers lower the platform figure, and agency and creative costs raise yours, so the two numbers usually differ.

Is it okay to lose money on the first order?

It can be, if customers reliably come back and you have the cash to wait. Brands with strong repeat purchase rates often accept a negative first-order profit to grow faster. Check your LTV and payback period before doing this deliberately, and set a limit on how negative you will go.

How can I lower CAC for my store?

Test more creative angles and hooks, improve product page conversion rate, raise first-order value with bundles, and tighten tracking so the algorithm optimises on accurate purchase data. Better conversion rate and higher order value make every ad dollar more productive, which brings CAC down without cutting spend.

How often should I calculate CAC?

Monthly is the most useful cadence, because weekly figures are distorted by sales, payday cycles and delayed conversions. Review it whenever you make a large budget change or launch a new channel. Keep the definition of acquisition costs the same each month so you are comparing like with like over time.

Is your CAC rising faster than your sales?

Book a Brand Growth Audit. We review your ad account, creative and store together and find the levers that bring acquisition cost back down. Book a Brand Growth Audit.