Amazon FBA Storage Fee Calculator

How Amazon FBA Storage Fees Work

Amazon charges monthly inventory storage fees for every cubic foot of warehouse space your products occupy in fulfillment centers. These fees are calculated based on the daily average volume of inventory stored during the month, multiplied by the applicable rate for your product's size tier and the current season. Standard-size products are charged $0.87 per cubic foot from January through September and $2.40 per cubic foot during peak season (October through December). Oversize products have lower rates at $0.56 and $1.40 respectively, reflecting how Amazon warehouses handle larger items differently.

The cubic footage of each unit is calculated by multiplying the product's length, width, and height in inches and dividing by 1,728 to convert to cubic feet. The total storage volume is then multiplied by the number of units stored and the per-cubic-foot rate. Understanding these calculations helps sellers forecast their monthly holding costs and make informed decisions about inventory levels, especially during the expensive peak season when rates nearly triple.

Aged Inventory Surcharge Explained

Amazon applies an aged inventory surcharge on products stored in fulfillment centers for more than 180 days. This surcharge increases progressively the longer inventory sits unsold. Products stored 181 to 210 days incur $1.50 per cubic foot or $0.50 per unit, whichever is greater. The surcharge escalates through multiple tiers, reaching $7.20 per cubic foot or $2.40 per unit for items stored 331 to 365 days. Inventory aged beyond 365 days faces a $6.90 per cubic foot surcharge plus an additional $0.15 per unit.

These surcharges can dramatically increase storage costs for slow-moving products. A standard-size item costing $0.87 per cubic foot in monthly storage could face an additional $7.20 per cubic foot in aged inventory surcharges if left unsold for nearly a year. Sellers should monitor their Inventory Age reports in Seller Central and create removal orders or run promotions before inventory crosses the 180-day threshold. The FBA Inventory Age tool shows exactly how many units are approaching each surcharge tier.

Standard vs Oversize Storage Rates

Amazon classifies products into two storage categories: standard-size and oversize. Standard-size items must have dimensions no larger than 18 x 14 x 8 inches and weigh no more than 20 pounds when fully packaged. Any product exceeding these limits is classified as oversize. Interestingly, oversize products have lower per-cubic-foot storage rates than standard-size items. During January through September, standard-size storage costs $0.87 per cubic foot while oversize costs only $0.56. During peak season, standard-size jumps to $2.40 versus $1.40 for oversize.

However, since oversize products occupy more cubic feet per unit, the total storage cost per unit is typically higher for oversize items despite the lower per-cubic-foot rate. This calculator automatically detects the size tier from your product dimensions or allows manual selection, making it easy to compare costs and plan inventory strategy accordingly.

Tips to Minimize Amazon Storage Costs

The most effective strategy for reducing storage costs is maintaining lean inventory levels. Order smaller, more frequent shipments rather than storing months of supply in Amazon's warehouses. Use the Restock Inventory tool in Seller Central to optimize replenishment timing and quantities. During the transition from standard to peak season in October, reduce inventory levels to avoid paying nearly three times the standard rate on excess stock.

Monitor your Inventory Performance Index (IPI) score to maintain storage capacity. Create removal orders for stale inventory before it hits the 180-day aged surcharge threshold. Consider multi-channel fulfillment or third-party logistics for slow-moving SKUs. Running periodic promotions, coupons, or lightning deals can help move aging inventory before surcharges apply. Every dollar saved on storage fees goes directly to your bottom line.