Shipping Calculations

Zonos Checkout and Zonos API supports calculating shipping rates for a variety of different express carriers, postal carriers, freight (LTL) as well as the ability to service custom service levels, transit times, rates and more. For shipments originating from the United States, both lbs and oz can be used to calculate shipping.

Decoding Cross-Border Shipping Calculations

In the simplest form, shipping calculations require a ship from address, a ship to address, and a package weight. As anyone who has shipped internationally can attest, this becomes notably more complex when you factor in billable weight, multiple carriers, service level weight, dimensional weight, additional fees, and item restrictions. All of this can prevent many from even attempting cross-border. Calculating international shipping costs doesn’t have to be a “guess” or manual process. Zonos’ API integrations, custom rate charts, proprietary rules engine, cartonization and multi-carrier support makes calculating cross-border shipments simple allowing you to focus on other aspects of your business.

Carrier API Integrations

Zonos offers the ability to connect directly with your carriers API to pull your negotiated rates. We support a direct integration with UPS, FedEx, and DHL and USPS. Set-up and integrated any of these carriers service levels with a few simple steps inside the Zonos™ platform. These prebuilt integrations allow you to display your rates inside the Zonos checkout in minutes.

Custom Rates

Surface shipping rates for any carrier or 3PL you can imagine, or just have your custom rates that you’d like to show at checkout. Being carrier agnostic allows you to maintain power and control, so your cross-border solution doesn’t need to change when your carrier does. You can upload custom rate charts giving you complete control of what rates you show and when. Have flat-rates that you want to show per country or by weight, Zonos makes that easy to do as well.

Robbi Rules

Many companies have complex products and shipping rules that e-commerce platforms and shipping software just can’t handle. Robbi (Zonos’ proprietary rules engine) gives you unlimited possibilities when it comes to managing that data. For example, many items are not available for air shipments and must be shipped via ground. Robbi makes sure that only ground options are shown at checkout. Want to offer free shipping on orders over a certain value, Robbi does that too. Robbi becomes your favorite over-worked under-paid employee, ensuring your complex shipping rules and calculations are shown correctly to your customer at the time of checkout. Learn more about Robbi’s computing capabilities and see the creative rules other companies utilize to compute complex calculations, outcomes, and scenarios.

Weights and Dimensions

Weight is key when calculating shipping costs accurately, Billable Weight to be more precise. Weights and dimensions can be passed via the Zonos API, through one of our extensions, or can be uploaded and maintained inside of Zonos. Although having your products actual weight or dimensions is preferred, Zonos works with many merchants that don’t have this data and are still able to estimate a shipping quote very accurately through a variety of rules and algorithms. You now can confidently ship cross-border without some of the seemingly necessary information.

Additional Carrier Fees

It’s important to be aware of additional charges that can occur in addition to your standard shipping costs. Many of which will not be calculated unless specific information is sent to your carriers API or you have the logic built into your shipping software. Standard fees include fuel surcharges, out of area fees, residential surcharge, additional handling surcharge and oversize fees. Some of these fees may add over $100 to what would normally be a $30 shipment. Zonos shipping calculations help to ensure these fees are included when they should be to make sure you aren’t losing money with shipping.

Examples of common additional carrier fees

Carrier Name Description Fee
UPS Over Maximum Limits weight > 150 lbs or length > 108in or length + girth > 165in $110 / pkg
FedEx Oversize Charge length > 108in or length + girth > 130in $72.50 / pkg
DHL eCommerce Oversize / Overweight length > 48in / weight > 150lbs $72.50 / pkg
UPS Extended Area Surcharge Packages picked-up or delivered in an extended area > of $30.00 / shipment or 0.30¢ / pound
FedEx International Out-of-Delivery(Pickup)-Area Surcharge Packages picked-up or delivered in an extended area > of $34 / shipment or $0.34 / lb
DHL eCommerce Remote Area Service Packages picked-up or delivered in a remote area > of $34 / shipment or $0.34 / lb


Zonos cartonization tool can be used to help determine the best box size for each order and uses that info to display the most accurate quote possible. With the necessary data such as item weight, dimensions and your box sizes, each item in every order runs through cartonization tool to determine the most optimal box to ship that order to give your customers the lowest shipping quote possible helping to capture more orders and checkout.

Shipping Buffers and Fees

Buffers and additional charges can be added to the shipping quickly inside of the Zonos platform. Increase shipping costs by a percentage, by a flat rate, by a carrier, or by service level. Zonos also can add part of all of our fees into the shipping cost so that you can pass our fees onto the customer allowing you to use Zonos at no additional cost to you. However, when purchasing from US websites, any increase in shipping costs can adversely affect your conversion.

Domestic Shipping Calculations

It is important to give your international customers domestic shipping options as well. Many international customers will ship to freight forwarders, family, or locations close to the US Border to save on shipping and other fees. Having a domestic shipping option in the Zonos checkout allows a more seamless shopping experience while allowing you, the merchant, to utilize the shipping rules and possible [fraud] tools and protection for those your international customers. Zonos can add a default shipping service level like UPS Ground or USPS, but if you have a flat rate or free shipping set-up on your domestic cart, discrepancies may cause issues and put you out of compliance with Google Adwords. We highly recommend matching your domestic shipping providers and prices to the US in the Zonos Checkout

The United States is enabled automatically when you set up your Zonos Checkout. There are multiple reasons to let Zonos manage orders shipping domestically. For instance, if the IP of the individual is outside of the United States the welcome mat will set their flag to their current countries location. When the customer goes to checkout, they will be directed to the Zonos Checkout and would get blocked from completing the purchase if you did not enable the US as a shipping destination. Also, when a customer is billing to a foreign address, it may make sense to have Zonos fraud screening help manage the additional risk, especially if you do not allow a customer to bill to an address outside the United States inside of your eCommerce platform. If they are paying with a non-US credit card they may have shopped and expected to pay in their local currency but ship to a US address. You can still decide what fits best with your business and manage country destinations inside of Zonos

Using Zonos Checkout Exclusively

Although Zonos was built specifically for cross-border and international transactions, many of the services and tools we provide has allowed some merchants to offer a better checkout experience for their domestic customers and manage complex shipping rules that they were unable to handle with their existing shopping cart platform. If you feel like Zonos Checkout could help with your domestic checkout experience as well, please contact us for custom pricing.

Zonos Recommends

First, customers want to know what it’s going to cost to get your product to their doorstep at time of checkout. Having to email or wait for a quote has become a burden in today’s “I want it now” world. The ability to surface the best rate at the time of checkout, without the worry of losing money on shipping is crucial. Second, ensuring that you aren’t losing money or subsidizing more than expected is critical to your international success. Zonos recommends running shipping audits for the first few months to verify shipping quotes are where they should be and making any necessary adjustments early.
Third, if possible, flat-rate shipping is very appealing to the international customer. When possible, offering that to even your higher traffic countries will result in higher conversion and more repeat customers.