Amazon FBA Calculator

The Amazon FBA calculator shows how much money is actually left over after the Amazon fees are taken out per sale. After entering in your selling price, product cost and some packaging information it calculates the sales fee, shipping fee, storage fee as well as net profit per item.

Most sellers overestimate their profit margins because they forget that several separate costs can add up. This tool will list all the costs individually so you can price your products correctly, compare suppliers or decide whether a particular product is worth stocking before placing an order.

What the computer calculates:

Every field ultimately affects one number: the profit per item. The calculator starts with the selling price and then subtracts all costs in sequence.

He estimates three types of fees Amazon charges for FBA orders. The selling fee is a percentage of the sale price. The shipping fee is a flat rate that depends on the size class and weight of the product. The monthly storage fee depends on how much space the product takes up in the warehouse.

In addition to Amazon's fees, your own costs are deducted: the cost of the product itself, shipping costs for getting it into the warehouse and any other costs you've selected such as prep work, advertising or taxes. The remaining amount is your net profit, which the calculator also shows as a profit margin and return on investment.

Here's how it works.

Start with the three values you always know: selling price, product cost and shipping costs for a single product to Amazon. Pick out the category that fits your offering since commission rates vary by category.

Then enter the length, width, height and weight of your package. This information determines the size category which affects shipping and storage costs. If your supplier gives prices in centimeters or kilograms, simply change the units; the calculator will automatically convert them to inches and pounds used by Amazon.

If you have to pay preparation costs, advertise or even charge sales tax, activate the corresponding section "Other Costs". If this area is deactivated, these positions will be shown as zero by default.

Formula for profit:

The net profit is equal to the selling price minus all costs and fees.

Profit margin and return on investment are both directly derived from profit. Profit margin is calculated based on the selling price while return on investment is calculated based on the cash invested which is the cost of the product plus shipping for storage:

Example calculation:

Suppose you sell a household item for $25 with product costs of $5 and shipping cost to store is $1. It's a small standard size measuring 8 x 6 x 2 inches and weighs 0.75 pounds; the month is a standard storage month, and there are no additional charges.

The commission for selling is 15%, which means a commission of $3.75 at the sale price of $25. The shipping cost for this size and weight is about $4.51. Because it's such a small package, storage costs are only a few cents. Adding up the product cost of $5 and the shipping cost of $1, the total cost comes to about $14.30.

The profit is thus about $10.70. At a selling price of $25, the profit margin is 42.8%. In relation to the invested $6 cash, the capital return is 178%.

Sales commission by product category.

Commission is calculated as a percentage of the sale price and varies by product category. For most categories it's 15%, but some have different rates, and some change their rate once a certain price threshold is reached, so picking your category is important.

Size chart and shipping costs

Amazon uses different size tiers for shipping orders and the size determines the shipping cost. The tiers range from small standard to large standard to oversize and bulky items. The heavier and larger the package is, the higher the cost will be. For all items that are larger than small standard, the shipping cost is calculated based on the higher value between actual weight and volumetric weight. So light but bulky boxes will be charged at a higher weight.

Even slight changes to the size or weight of a package can cause an item to fall into the next tier of sizes, which will increase your cost per item by $1 or more. If your products are close to a size threshold, it is recommended that you test both sides of the threshold before finalizing packaging.

Storage and seasonal fluctuations

The monthly storage fees are calculated based on the number of cubic feet your inventory occupies. During peak season from October to December, the storage costs increase as Amazon warehouses fill up in preparation for the holiday rush. The per-cubic-foot storage cost is higher for standard-sized items than it is for oversize items, but oversize items take up significantly more space so that overall cost is often higher.

Slow-moving inventory can lead to long-term storage costs that this tool does not take into account. Fast turnover of goods allows you to reduce the cost of keeping them in stock, thus improving your profit margin.

How to get more realistic estimates:

Use the actual cost of importing a product rather than just relying on the supplier's stated unit price. Customs duties, shipping costs and prep costs should be included in this calculation; leaving these out is often what causes the actual profit margin to fall short of expectations.

Consider advertising expenses as part of the actual cost per unit. Many products can only be sold with advertising and once the costs of advertising required to sell them are factored in, a promising profit margin at first may disappear.

This calculator provides estimates based on the standard FBA fee structure in the US for 2026. Actual fees will depend on your account, product details and Amazon's current rates and are subject to change at any time without notice. Please visit Seller Central to see the exact fees for your products.