What are unit economics?

Unit economics are the revenues and costs of a single unit of the business. For an ecommerce store the unit is usually an order or a customer. Healthy unit economics mean each one produces more contribution than it costs, so growth adds profit instead of losses.

How do you calculate unit economics for an ecommerce business?

Work out the contribution of one order: average order value minus product cost, shipping, fulfillment, payment fees and returns. Multiply by the number of orders a customer places over their lifetime, then subtract customer acquisition cost. The result is the profit each customer produces.

What is the difference between unit economics and contribution margin?

Contribution margin is one part of unit economics: what an order leaves after variable costs. Unit economics adds the cost of acquiring the customer and how many orders they place, to show whether the customer relationship as a whole is profitable.

Is it bad if the first order loses money?

Not necessarily. Many healthy stores lose money on a customer's first order once acquisition cost is counted, and make it back on later orders. It becomes a problem when repeat purchases are not strong enough to recover the loss, or when they take so long that cash runs out first.

What is a good LTV to CAC ratio for ecommerce?

3:1 is the most common benchmark: lifetime contribution about three times acquisition cost. Below 1:1, every customer loses money over their whole relationship with you.

Ecommerce Unit Economics: A Calculator & Guide

Revenue growth feels like progress. But if each customer costs more to acquire and serve than they bring in, growing faster just means losing money faster.

Unit economics is how you tell the difference. It strips the business down to a single unit, one order or one customer, and asks whether that unit makes money. If it does, growth builds a better business. If it does not, no amount of scale will fix it.

The two units that matter

For an ecommerce store there are two useful units.

The order. What does one order leave after the costs that come with it? That is contribution per order, covered in depth in the contribution margin guide.

The customer. What does one customer leave after you have paid to acquire them and served every order they place? That is where acquisition cost and repeat purchases come in.

You need both. A store can have healthy order economics and unhealthy customer economics, if acquisition costs more than customers ever pay back.

Calculating unit economics

Step 1: contribution per order.

Contribution per order = Order value − Product cost − Shipping and fulfillment − Fees and returns

With the calculator’s starting numbers, a $75 order carrying $28 of product cost, $10 of shipping and fulfillment and 6% for payment fees and returns ($4.50) contributes $32.50.

Step 2: first-order profit.

First-order profit = Contribution per order − Customer acquisition cost

With a customer acquisition cost of $45, the first order loses $12.50.

Step 3: lifetime profit per customer.

Lifetime profit = Contribution per order × Lifetime orders − Customer acquisition cost

If the average customer places 2.5 orders over their lifetime, they contribute $32.50 × 2.5 = $81.25. After the $45 acquisition cost, each customer produces $36.25 of profit. That is the number that has to pay for the team, the software and the rent.

Reading the result

The example produces three useful signals.

LTV to CAC of 1.81. Lifetime contribution of $81.25 against a $45 acquisition cost. Positive, but short of the commonly quoted 3:1 target. The store makes money on each customer, but not with much room for error.

Payback in 1.38 orders. It takes $45 ÷ $32.50 = 1.38 orders to recover the acquisition cost. Every customer who buys only once is a loss. The business depends on a healthy share of customers coming back, so its repeat purchase rate matters enormously.

Lifetime profit of $36.25. Multiply by the number of new customers a month and compare it with fixed costs. If 600 new customers a month produce $21,750 of lifetime profit, but that profit arrives over two or three years while the fixed costs arrive every month, cash flow will be tight even though the unit economics are positive.

Losing money on the first order

Losing money on the first order is normal for many stores, and it is not a problem on its own. It is a bet that repeat purchases will recover the loss.

The bet is sound when:

repeat purchase data from real cohorts, not a forecast, shows customers coming back often enough to pay back acquisition,
payback happens fast enough that you are not waiting years to recover cash, and
acquisition costs are stable, not rising every quarter.

It becomes dangerous when lifetime orders are assumed rather than measured, when acquisition costs keep climbing, or when the business needs the second order to survive but has no reliable way to earn it.

The five levers

Every input in the calculator is a lever, and each one improves unit economics in a different way.

Raise order value. A bigger average order value spreads shipping and fulfillment over more revenue, lifting contribution per order.
Cut variable costs. Better carrier rates, lower fulfillment costs, fewer returns and lower payment fees all flow straight into contribution per order.
Lower acquisition cost. Better conversion rates, sharper targeting and channels that compound all reduce what each customer costs.
Increase lifetime orders. Earning the second order and the third is usually the biggest lever of all, because each one adds contribution with almost no acquisition cost. See customer lifetime value.
Protect margin on repeat orders. Discounting every repeat order erodes the very contribution that makes the unit economics work.

Small changes compound. In the example, raising lifetime orders from 2.5 to 3.0 lifts lifetime profit per customer from $36.25 to $52.50, a 45% improvement, without changing anything else.

Unit economics vs the profit and loss statement

Your profit and loss statement tells you whether the business made money last month. Unit economics tells you whether the business model makes money.

A store can show a loss while its unit economics are healthy, typically when it is investing heavily in acquisition and the repeat purchases have not arrived yet. And a store can show a profit while its unit economics are deteriorating, typically when it is coasting on returning customers acquired years ago while new customers cost more than they will ever repay.

Watching both is how you spot the second situation before it becomes a crisis.

Put it to work

Put your real averages into the calculator above, using lifetime orders you can support with cohort data rather than hope. If lifetime profit per customer is thin or negative, find the lever with the most room to move. For most established stores, that is not acquisition. It is order value, margin and repeat purchases. For how all the metrics connect, see the ecommerce metrics that drive profit.

Unit Economics for Ecommerce: Does Each Customer Make You Money?

Ecommerce unit economics calculator