Shipping and inventory tools
Free calculators and guides for the numbers behind shipping, freight and inventory. Each one runs in your browser, explains its math and links to the rule it follows.
Shipping and carriers
Billable weight, zones, size limits, tracking and holiday cutoffs.
- Shipping zone mapEstimated shipping zones from five U.S. warehouses to the 150 largest metros.
- Dimensional weight calculatorWhat UPS, FedEx and USPS bill for a box, with the 2026 divisors.
- Holiday shipping deadlinesUSPS and FedEx last days to ship for Christmas 2026, with a countdown.
- Shipping zone calculatorThe estimated USPS zone between any two ZIP codes, on a live map.
- Tracking number lookupWhich carrier a tracking number belongs to, from its format.
- Package size limitsLength plus girth and weight limits for USPS, UPS and FedEx, checked against your box.
Freight and imports
Containers, cubic meters, freight class, landed cost and Incoterms.
- Container loading calculatorHow many cartons fit in a 20 ft, 40 ft or 40 ft high cube container.
- CBM calculatorCubic meters, cubic feet and chargeable weight for a mixed shipment.
- Freight class calculatorLTL freight class from weight and dimensions on the 13-band NMFC density scale.
- Landed cost calculatorWhat each imported unit really costs once freight, duty and customs fees are added.
- Incoterms 2020 chartWhere risk passes and who pays carriage, clearance and insurance under each rule.
Inventory planning
When to reorder, how much to keep and how fast stock turns.
- Reorder point calculatorWhen to reorder a SKU, from daily demand, lead time and safety stock.
- Safety stock calculatorHow much buffer stock to hold for the service level you want.
- EOQ calculatorThe order size with the lowest yearly ordering and holding cost.
- Inventory turnover calculatorHow many times your stock sells through in a year, and days on hand.
- Return rate calculatorWhat returns cost you, and how much restocking wins back.
Warehousing
Pallets, storage and what happens inside a 3PL warehouse.
Reference
Plain-English definitions of the terms on your 3PL invoice.
Common questions
Are these tools free?
Yes. Every tool runs in your browser without an account, and nothing you type is sent anywhere.
Where do the numbers come from?
Carrier and customs rules come from the carrier or agency publications linked on each page, checked on the date shown there. Fulfillment Hub USA rates come from our published pricing.
Can Fulfillment Hub USA run this for me?
Yes. Share your products, order volume and where your customers are, and we’ll come back with an itemized fulfillment quote.
Ready to hand off the shipping?
Tell us your products, order volume and where your customers are, and we’ll come back with an itemized fulfillment quote.