What this calculator does
Customer lifetime value estimates the total profit one customer generates across the whole relationship, not just the first order. This calculator multiplies order value, purchase frequency, expected lifespan and margin, then compares the result against your acquisition cost so you can see whether what you pay for customers is justified.
How to use it
- Enter your average order value.
- Enter purchases per month. If a typical customer buys roughly every seven weeks, that is about 0.6.
- Enter the customer lifespan in months — how long they keep buying before going quiet.
- Enter your profit margin so the result is profit rather than revenue.
- Add your customer acquisition cost to see the CLV to CAC ratio, which is the number that actually matters.
The formula, explained
This is the simple, practical version of lifetime value. More elaborate models discount future revenue and model churn statistically, but for a store with under a few thousand customers the extra precision rarely changes a decision.
The ratio is what to watch. A widely used rule of thumb is that lifetime value should be at least three times acquisition cost. Below that there is not enough left over to cover fixed costs and fund growth at the same time.
A worked example
A supplements store has a 49.99 AOV, customers order about 0.6 times a month, stay for roughly 14 months, and the margin is 32%. Acquisition cost is 12.50.
That is 8.4 orders and 419.92 of lifetime revenue, giving a CLV of 134.37. Against a 12.50 CAC the ratio is 10.7 to 1, which is exceptionally healthy and means the store could afford to pay considerably more per customer than it currently does — often the single biggest missed opportunity in a consumable-product business.
| Average order value | 49.99 |
|---|---|
| Orders per customer | 8.4 |
| Lifetime revenue | 419.92 |
| Customer lifetime value | 134.37 |
| CLV : CAC ratio | 10.75× |
What a good result looks like
The CLV to CAC ratio is the standard health check. These bands apply across most consumer ecommerce.
| Range | What it means |
|---|---|
| Above 3:1 | Healthy. There is room to reinvest in acquisition confidently. |
| 2:1 to 3:1 | Acceptable, but fixed costs will absorb much of the difference. |
| 1:1 to 2:1 | Tight. Growth will not fund itself at this ratio. |
| Below 1:1 | You pay more for a customer than they are ever worth. This does not scale. |
Common mistakes
- Using revenue instead of profit. Lifetime revenue looks impressive and means nothing on its own. Always apply the margin, or you will overpay for customers.
- Assuming every product has repeat purchases. A mattress or a suitcase is a one-off for most people. For those products, first-order economics are the only economics.
- Guessing lifespan optimistically. If you have six months of data, do not model fourteen months of loyalty. Use what you can observe and revise as you learn.
- Ignoring the payback period. A high CLV that takes two years to realise does not pay this month's invoices. Cash flow matters as much as lifetime value.
- Applying one CLV to every acquisition channel. Customers from a discount code campaign usually have far lower lifetime value than those from organic search. Segment before you spend against the number.
Frequently asked questions
What is a good CLV to CAC ratio?
Three to one is the conventional benchmark: for every unit you spend acquiring a customer, you want three back in lifetime profit. Below two to one, fixed costs and the delay between spending and earning make growth uncomfortable. Well above five to one usually means you are underinvesting in acquisition.
How do I estimate customer lifespan without much data?
Start conservatively — three to six months for a new store — and use the repeat purchase pattern of the product category as a guide. Consumables repeat within weeks, apparel within months, durable goods rarely. Update the number as your own cohort data accumulates.
Should I include shipping costs in the margin?
Yes. Use your net margin after product cost, shipping and payment fees, exactly as the profit margin calculator reports it. Using gross margin inflates CLV and leads to overpaying for acquisition.
Can I use CLV to justify losing money on the first order?
Only if you have data showing genuine repeat purchases and the cash to fund the gap. Many stores have failed by paying for lifetime value they had not yet earned. Prove the repeat rate first, then increase acquisition spend.
How is CLV different from average order value?
AOV measures one order; CLV measures the whole relationship in profit terms. A store with a modest AOV but frequent repeat purchases can have a far higher lifetime value than one with expensive one-off orders, and can therefore outbid it for customers.
How this fits with your other numbers
Lifetime value is what allows a store to outbid its competitors. If you know a customer is worth three orders and your competitor is pricing on one, you can pay more for the same click and still make more money. That is the whole advantage, and it depends entirely on having repeat purchase data you can trust.
Be conservative until you have that data. Modelling fourteen months of loyalty on six weeks of trading is how stores end up spending money they have not earned. Start with what you can observe, revisit the number each quarter as cohorts mature, and only raise your acquisition ceiling once the repeat rate has proved itself over a full purchase cycle.