How to calculate customer lifetime value

Aug 18
3 min read

Updated: Aug 27

Introduction

Customer lifetime value is the total profit one customer produces over the whole time they buy from you. It matters because it is the only number that tells you what a customer is actually worth — and therefore the most you can sensibly pay to get one.

Most small businesses never calculate it. They track cost per lead and monthly revenue, both of which can look healthy while the business quietly loses money on every new customer. Here is how to work it out, and what to do with the answer.

1. The three numbers you need

You need three figures. All of them are already sitting in your sales records.

Average order value

Total revenue divided by number of orders, over a fixed period. If you took $40,000 across 1,000 orders last year, your average order value is $40.

Purchase frequency

Number of orders divided by number of unique customers, over the same period. If those 1,000 orders came from 400 customers, each customer bought 2.5 times.

Customer lifespan

How long a customer keeps buying, in years. If you have no history yet, estimate conservatively — one year is a safe starting point, and you can refine it as data accumulates.

2. How to calculate customer lifetime value: the basic formula

Customer lifetime value = average order value × purchase frequency × customer lifespan

Using the numbers above, with a two-year lifespan:

$40 × 2.5 × 2 = $200

So an average customer is worth $200 in revenue.

3. The version that actually matters

Revenue is not profit. A $200 customer on a 30% margin produces $60, not $200 — and $60 is the figure your acquisition spend has to fit inside.

CLV (profit) = average order value × purchase frequency × lifespan × gross margin
$40 × 2.5 × 2 × 0.30 = $60

This is the number to use. Businesses that plan against revenue CLV routinely overspend on acquisition and cannot work out why growth is not producing profit.

4. What the number is for

Calculating it is not the point. Deciding with it is.

Setting a ceiling on acquisition cost

If a customer produces $60 in gross profit, then $60 is the absolute maximum you can pay to acquire one — and paying the maximum leaves you nothing. A sensible working ceiling is a third of profit CLV, so around $20 in this example.

Now your ad performance has a pass mark. A campaign at $15 per customer is working. A campaign at $45 is losing money, no matter how good the engagement looks.

Deciding where to spend next

CLV has three inputs, which means three ways to raise it: get customers to spend more per order, buy more often, or stay longer. Run each one through the formula and see which moves the number most for the least effort.

Frequency is usually the cheapest lever, because it acts on people who already know you. Raising frequency from 2.5 to 3.5 in the example above lifts profit CLV from $60 to $84 — a 40% increase, without a single new customer.

5. Common mistakes

Using revenue instead of margin. The single most expensive error. It inflates your acquisition ceiling and hides the losses.

Averaging across very different customers. If you serve both one-off buyers and long-term regulars, one blended CLV describes nobody. Segment them and calculate separately.

Guessing lifespan optimistically. A three-year assumption you cannot evidence will justify spending you should not do. Start with what your records support.

Calculating it once. CLV moves whenever pricing, margin or retention changes. It belongs on a dashboard you look at, not in a spreadsheet you built in January.

6. Getting it onto a dashboard

You do not need paid software for this. Sales exports plus a free reporting tool such as Google Looker Studio will hold all three inputs and recalculate CLV as data arrives.

What makes it useful is putting acquisition cost next to it. Those two figures side by side — what a customer costs and what a customer is worth — answer most spending questions without a meeting.

Conclusion

Customer lifetime value takes about twenty minutes to calculate from records you already have, and it changes how every other marketing decision gets made. Work out the margin-adjusted version, divide by three to set your acquisition ceiling, and then look at which of the three inputs is cheapest to improve.

Do that and you stop asking whether marketing is working, which is unanswerable, and start asking whether each customer costs less than they are worth — which has a number attached.