Amazon Low Inventory Fee Calculator

How to Use the Calculator

The Amazon Low Inventory Fee Calculator helps you quickly estimate how much the fee on units below the inventory threshold may cost you. Enter two values: Units below threshold and Fee / unit. The tool defaults to 400 units and $0.30 per unit, but you can change them to your own values.

After you enter the data, you immediately see two results: Penalty / month and Penalty / year. The calculator uses simple math: monthly penalty = units below threshold times fee per unit, and yearly penalty = units below threshold times fee per unit times 12. For the default values, you get $120.00 per month and $1,440.00 per year.

Amounts are shown in US dollars ($). The fee per unit is editable, so you can test your own rate; the calculator does not convert currencies. Keep in mind that rates are estimates and editable; before making a decision, check Amazon's current pricing.

What the Amazon Low Inventory Fee Is

The low inventory fee is a fee Amazon may charge when some of your products have too little inventory relative to demand or when you keep too few units to fulfill orders smoothly. The definition mentions an inventory threshold below 28 days, but the calculator itself has no days-of-supply logic or 28-day threshold. You enter the number of units subject to the fee.

The purpose of this fee is to encourage sellers to keep inventory at a level that reduces the risk of stockouts and delays. In practice, this means that if you sell on Amazon and part of your catalog sells faster than you replenish it, you may incur extra costs.

The calculator does not replace an analysis of your account or reports. It does let you quickly calculate what monthly and yearly cost a given number of fee-bearing units may produce at the rate you enter.

How to Determine the Number of Units Subject to the Fee

The number of units subject to the fee is the most important variable in this calculator. No automatic rule based on days of supply calculates it for you. You decide how many units to include in the calculation. You can use a number from a report, from Seller Central, or your own estimate based on sales history.

Think about which products may actually be subject to the fee. Sometimes it will be one SKU, and sometimes it will be the sum of several products. If you want to test several scenarios, calculate each one separately and compare the results. Enter a whole number of units, such as 400, and then adjust the fee per unit.

Remember that units and rate are connected: the more units below the threshold and the higher the per-unit fee, the larger the monthly and yearly penalty. This makes it easy to check whether it is worth prioritizing replenishment for a specific inventory item.

Rates Based on Size Tier and Days of Supply

For Amazon, low inventory fee rates may depend on the product size tier and the number of days of supply. The calculator does not automatically recognize either size tier or days of supply. It also does not apply a 28-day threshold in its calculations. Instead, it uses one fee per unit that you enter yourself.

This lets you quickly calculate different scenarios: for example, one rate for small products and another for larger ones. In the Fee / unit field, enter the amount that matches your scenario. The default value is $0.30 per unit, but it is only a starting point and you can change it.

Do not treat the default rate as current pricing. Always check current rates for your size tier and inventory situation in official Amazon information. Amounts in the calculator are in US dollars ($), but you can enter your own numeric rate for any scenario; the calculator does not convert currencies.

Limitations and What the Tool Does Not Calculate

The Amazon Low Inventory Fee Calculator is an estimation tool. It does not automatically account for fees, taxes, current exchange rates, individual contract terms, or changes to platform pricing. It also does not analyze days of supply or the 28-day threshold — that information is only mentioned in the definition, not part of the calculation.

The tool does not import or export files. Calculations run locally in your browser, and the tool does not send data. All you do is enter the number of units and the fee per unit and read the monthly and yearly penalty.

The result is only an estimate based on your assumptions. It can help with budget planning, comparing scenarios, and quickly judging the scale of the cost, but it does not replace an Amazon settlement or accounting analysis. Before making a decision, check current pricing and your actual sales data.

Frequently Asked Questions

Amazon rates and rules are approximate and may change — before making a decision, check current pricing and Seller Central for your marketplace.