How to set a minimum order value: break-even cart and lost customers

A minimum order value starts from the cart value at which an order begins to cover its own cost. You find it by dividing the avoidable cost per order by the contribution margin rate. But that calculation alone does not give the right minimum.

The decision changes with how many customers below the minimum fill their cart and how many give up. It also depends on how much future contribution is lost because of the minimum.

This guide calculates a minimum order value for one hypothetical store. It compares three minimums, shows which assumptions change the result, and explains when a small-order fee may be a better option than a minimum.

Every order carries a cost that does not depend on the cart value. One example is the part of the carrier's charge that the shipping fee does not cover. Others are picking and packing and the fixed part of payment processing. If the cart is small, the margin on the products does not cover this cost and the order loses money.

A minimum order value either makes these orders larger or turns them away. That makes it different from a free shipping threshold.

A free shipping threshold gives orders above it a benefit and still accepts orders below it. A minimum order value refuses orders below it. The free shipping threshold guide explains how to calculate a threshold.

For an order not to lose money, the margin on its products must equal the cost per order. So the break-even cart value is that cost divided by the contribution margin rate. Contribution margin here is what remains after product cost and the costs that grow with cart value. You can find gross margin with the gross margin calculator and subtract the other proportional costs from it.

The cost per order in this calculation should be a cost that disappears when no order is placed. The shipping gap, packing materials and transaction fees are examples. A share of overheads such as customer service salaries or warehouse rent does not disappear when one order is refused. If you count that share, you overstate the benefit of a minimum.

Do not count the same cost twice when you split them. Costs that grow with cart value, such as payment fees, belong in the contribution margin. Costs that do not depend on value belong in the cost per order.

Hypothetical example: a store has an avoidable cost of $7 per order and a 35% contribution margin. Its break-even cart value is $20. Every order below $20 loses money, and every order above it leaves a margin. Values are net of tax and returns.

The same store takes 2,000 orders a month. The table below shows the orders under $35 and the margin each one leaves. The 250 orders between $15 and $25 are split at the $20 break-even point, with 125 orders assumed in each half. The other 1,300 orders average $65 and are not affected by the minimum.

In this distribution average order value is about $50. A rule that appears often in guides says to keep the minimum below average order value. All three minimums compared here, $20, $25 and $35, follow that rule. So the rule does not choose between them.

You can check average order value (AOV) with the AOV calculator, but the information the decision needs is in the bands.

Each customer below the minimum does one of two things. They add items and pass the minimum, or they give up. In the example, a customer who fills their cart lands $1 above the minimum: $21, $26 or $36.

Compare three minimums

A customer who fills their cart raises the margin on their order. A customer who gives up takes that order's margin with them. Losing an order that loses money raises profit, and losing an order that leaves a margin lowers it. The table below assumes that 20% of customers below the minimum fill their cart and that no future contribution is lost because of the minimum.

The $20 minimum blocks only orders that lose money. The $25 minimum also blocks the $20–$25 orders, which leave a margin.

The $35 minimum adds the $25–$35 band, whose margin is higher still. Each customer who gives up in that band takes $3.50 of margin per order. So the higher the minimum, the more the result depends on how many customers fill their cart.

How the result changes when the assumptions change

The result above rests on two assumptions: how many customers fill their cart, and how much future contribution is lost because of the minimum. The two tables below vary them separately. Cost per order, contribution margin and the order distribution stay the same.

The first table shows only this month's margin change. The first three rows use the same fill rate for all three minimums. The last row uses different rates, since a higher minimum asks the customer to add more. They are 40% at $20, 30% at $25 and 15% at $35.

With equal fill rates, the $20 minimum gives the highest margin in the 10% scenario. The $35 minimum beats the $25 minimum only if more than about 34% of customers below it fill their cart. When fill rates fall as the minimum rises, as in the last row, the gain from the $35 minimum almost disappears.

The second table shows the total effect. That is this month's margin change minus the contribution lost over the next 12 months because of the minimum. It assumes each order given up belongs to a different customer. It also assumes $5 of contribution over the next 12 months is lost from each because of the minimum. The $5 is not the customer's whole future value, only the part lost because of the minimum.

In this scenario the total effect of all three minimums turns negative. If some customers who start with a small cart later return with large ones, a minimum can lose them on the first order. If a customer gives up this month and places a large order next month, the loss is close to zero. The real loss lies somewhere between these two ends.

Under the assumptions tested, these tables show how much margin each minimum leaves. They do not measure all of the risk, and they do not show which minimum is more profitable for your store. Only your own data and a test can tell you the fill rate and the future contribution lost because of the minimum.

Estimate the future contribution at risk from your data

The input with the biggest effect in the second table is the future contribution lost because of the minimum. To estimate it, look at your history.

Find customers from the past year or two whose first order was below the minimum. Then calculate the total margin they left over the following 12 months. You can also estimate this customer lifetime value (LTV) with the LTV calculator.

That figure does not tell you directly how much contribution the minimum will cost. It gives the upper bound of the contribution at risk, because some customers who give up come back later. Past data provides an input for scenarios. Only a control group that does not see the minimum shows how much is actually lost.

Count customers, not orders. If one customer gives up several orders, do not write the future loss against each order again. Also separate new customers whose first order was small from existing customers who place a small order.

A new customer's small first order can be the start of a relationship. A loyal customer's small extra order is usually a one-off top-up. The customer retention metrics guide covers how customers behave over time.

A field experiment suggests the risk of losing customers may be smaller than expected. A 2019 study by Lepthien and Clement assigned an online shop's visitors to seven shipping fee structures that varied minimum order sizes. It found no negative effect of a minimum order value on purchase incidence or purchase value. It did find slightly more returns by current customers.

That is one experiment in one shop. It does not show that your store will see the same result. It is a good reason to measure the give-up rate rather than assume it.

After you set a minimum, you need to separate three groups.

Flag a user who reaches checkout with a cart below the minimum as "blocked". That requires logging the moment the checkout warning appears as an event. A blocked user may place an order above the minimum in the same session or within a set period, such as seven days. Count them as "filled" if they do and "gave up" if they do not.

Set the period in advance and keep it the same for both groups. If it is too short, customers who return later look as if they gave up. Also split blocked users into new and existing customers. You can track the drop-off up to checkout with the funnel analysis calculator. Compare conversion rate before and after the minimum with the conversion rate calculator.

This definition shows a behaviour, not a cause. A user who gave up might have left without the minimum too. The reliable way to separate orders lost to the minimum is a control group that does not see it.

In the test, assign users rather than visits. The success metric is the total margin from a group's users divided by the number of users assigned to that group. Users who do not buy stay in the denominator. The control group guide explains how to set up the comparison group.

A minimum order value refuses a small order. A small-order fee accepts it but asks the customer to cover part of the cost the order does not.

The break-even fee is the average loss on orders below the break-even value. In the example, orders under $15 lose $3.15 on average. A $3.15 fee on those orders brings the group to break-even on average, if the cart distribution does not change.

Break-even on average is not break-even on every order. A $5 order still loses $2.10 with a $3.15 fee. If payment fees are also taken from the fee itself, the fee needs to be higher. A tiered fee for the smallest carts is one option.

A small-order fee is safer than a minimum when a lot of future contribution is at risk. The customer can still place a first order, and the store's loss on it shrinks. Some customers who see the fee may still give up. So measure the fee's effect with the same method as the minimum, using the same groups and periods.

Whichever you choose, tell the customer before checkout. Baymard Institute's cart abandonment research excludes "just browsing" respondents and looks at the remaining reasons. Among these, 40% cited extra costs such as shipping, tax and fees. Another 12% said they could not see or calculate the total order cost up front.

A minimum that a customer first sees at checkout comes as a surprise. So show it on product pages and in the cart, with how far the cart is from the minimum.

Also check how your platform applies it. On Shopify, an order minimum is set up with the order value limits feature in the Checkout Blocks app. Shopify says the limit is based on the subtotal before gift cards or store credit. So the amount a customer pays can fall below the minimum.

You can set a minimum order value in Google Merchant Center. Google says to set it only if you do not ship orders below that amount. If you still ship below the amount for a fee, set a free shipping threshold instead of a minimum.

If you send shipping details at product level, set the minimum at product level too. Google's minimum order value attribute page says a minimum set for a product overrides the account-level minimum. The same page asks you to set the minimum_order_value attribute if you use the shipping or carrier shipping attributes.

As costs per order and cart values change, the break-even value changes too. Recalculate the minimum when your carrier contract, packing costs or payment fees change. The steps below let you make the decision the same way each time.

1. List the costs per order that disappear when no order is placed, and the costs that grow with cart value, separately.
2. Divide the cost per order by the contribution margin rate to find the break-even cart value, and take it as one of the candidate minimums.
3. Split the last three months of orders into value bands, net of tax and returns, cut one band at the break-even value, and calculate the margin per order in each band.
4. Calculate from past data, per customer, the margin that customers with a small first order left over the following 12 months.
5. For each candidate minimum, calculate this month's effect and the total effect separately, across several fill rates and future losses.
6. Compare a minimum and a small-order fee under the same scenarios, then test the chosen option with a control group.

A minimum order value looks like a profit rule, but it is above all a customer decision. The break-even value tells you which orders lose money. Whether refusing those orders is right depends on what the customers who place them do next.