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Marilyn Bunderson

How to Calculate Shipping Costs

by Marilyn Bunderson
woman at computer calculating shipping costs

Customers look for fast and free delivery when they order online. A recent study by McKinsey and Companyopens in new tab found that more than 90% of consumers consider 2- and 3-day delivery to be a baseline expectation. And in a survey conducted by Digital Commerce 360opens in new tab, 76% of shoppers listed free shipping as the attribute or condition most likely to lead shoppers to a website. The right price took second place at 73%.

As an online retailer or ecommerce brand, you need to be able to accurately calculate shipping costs to fully understand the impact of shipping on your profit margins. Knowing how much it costs to ship your parcels is a critical component in pricing your products right. 

How do I calculate shipping costs? 

You’ll need to take several different factors into account as you calculate shipping costs. Weight, dimensions, value, and other variables affect the calculation, so it’s important to understand how each comes into play. 


The dimensional weight, or DIM weight, is a measure of the density of your package. It’s calculated by multiplying the length x width x height and then dividing by a carrier’s specific divisor. For oddly shaped packages, use the longest point on each side. 

Carriers like USPS, FedEx, UPS, and DHL calculate shipping charges based on the higher number between the actual weight and the dimensional weight of the package. Using the dimensional weight takes the size of the package into account, therefore guarding against issues like shipping a lightweight package that takes up a disproportionate amount of space. 

If you have a package that is 10x10x10, for example, use the sum of 1,000. For DHL, the divisor is 166 if you measured in inches and 6,000 if you used centimeters. Using inches, the dimensional weight of the package is 6 pounds. If the actual weight of the package is 5 pounds, the dimensional weight of 6 pounds would be the chargeable shipping weight. 

Carrier Divisors
(L x W x H)/166
(L x W x H)/139
(L x W x H)/166* 
(L x W x H)/166**

*UPS uses a divisor of 139 for Daily Rates and 166 for Retail Rates.

**DHL uses a divisor of 166 for inches and 6,000 for centimeters.

Tip: Make sure to use the right size package for the item you’re shipping. You’ll pay more for an unnecessarily big box.


If the package weight is more than the calculated dimensional weight, the actual weight of the package is used. Heavy packages use more resources to ship, so you’ll pay more in shipping costs to ship heavy items. 

Tip: In some cases, it may be worth it to break up heavy shipments into several smaller packages if that’s a possibility. A heavier package may be more likely to be dropped, especially when it’s too large to handle. In addition, overweight charges add up fast. 


Shipping zones are geographic areas carriers use to calculate shipping times and prices. The greater the shipping distance, the more it will cost to ship the item, so shipping within your zone will cost less. 

The United States is generally broken down into eight zones (USPS uses nine zones). Zone one is the origin of the shipment, and zone 8 (or 9 in the case of USPS) is the farthest possible distance for a domestic shipment. Some flat rate services are available, and those are not affected by zones. Flat rates allow you to ship anywhere in the U.S. for the same price regardless of the destination. 

Tip: When possible, distribute your products to warehouses throughout the country so you don’t have to ship long distances to get to your end destination. Your shipping will be cheaper, and you’ll get your packages there faster. 


The value of the item you’re shipping can impact the shipping charges if you want to include shipping insurance. If you choose to insure a package, you will receive reimbursement for lost, stolen, or damaged packages. The cost of insurance is generally a percentage of the value of the item being shipped.  

Tip: The USPS offers free shipping insurance for packages valued up to $100 for Commercial Plus customers. And when you have high-value packages, it’s generally worth it to provide insurance. 

Delivery times

A surveyopens in new tab of consumers who shop online at least once a month found that 41% expect delivery within 24 hours. Expectations for 1-2 day delivery are on the rise as well, and fast delivery will need to figure into your shipping cost calculations. 

Providing 2-day shipping to customers in the same zone you’re shipping from can be done through ground shipping. However, if you need to deliver to a customer in zone 8 or 9, you’ll need to use more expedited shipping options. Distance matters, so using a fulfillment center close to the destination will save you money.

Tip: Offer your customers free ground shipping and give them the option to pay for faster delivery. 


Shipping surcharges are extra fees added to the shipment that may show up as a service or handling fee. Surcharges could include the following: 

  • Fuel surcharge
  • Oversize package surcharge
  • Weekend delivery surcharge
  • Residential delivery surcharge
  • Signature required surcharge
  • Address correction surcharge
  • And more

Tip: Make sure you understand exactly what you are being charged and why. Often, you can take steps to minimize surcharges or even renegotiate contracts to eliminate them altogether. 

Duties and taxes

Goods transported across international borders must pay a tariff or tax. These Customs Dutiesopens in new tab, which are put in place to protect a country’s economy, can be paid by either the seller or the buyer. You can and should calculate these tariffs and taxes before you ship to gain full insight into your shipping costs. 

Shipping supplies

Not to be overlooked, shipping supplies can be a big part of your overall shipping costs. USPS does provide some free shipping materials for some levels of shipping, but even if those free resources work for you, you’ll likely need additional packing materials to keep your items safe. 

Tip: To save money on shipping supplies and packaging, consider making bulk purchases of boxes, packing peanuts, air pillows, tape, etc. In addition, make sure your packages or boxes are the right size for your product. Leaving extra space in your boxes means you’ve spent more on a larger box than is necessary, your shipping costs will be higher thanks to the larger box, and you’ll need to use more packing materials to keep your items safe. 

Unexpected events 

Delays, lost packages, damaged packages, and other issues will happen from time to time. Make sure you leave a little room in your budget for these unplanned events. 

Calculating shipping costs 

Every carrier has their own take on how to calculate shipping costs. It’s essential to understand how it works for each to make a well informed decision. 


The United States Postal Service (USPS) is government operated and provides some of the most cost-effective shipping services available. They offer a wide variety of shipping options, including First-Class Mail, Priority Mail, Express Mail, USPS Retail Ground and more. To calculate your postage, you can enter your information into a price calculatoropens in new tab on their website. 

Weight, size, shape, and distance will affect the cost of shipping. With Priority Mail you can ship a package up to 108 inches in length plus girth and up to 70 pounds. USPS Retail Ground, on the other hand limits you to 130 inches for the length and girth but with the same weight limit. If you go over that size or weight limit, you’ll need to pay an overweight charge. 

Shipping speed – how quickly you need your package delivered – also impacts the cost of shipping. The table below shows the cost of shipping a two pound package from San Francisco, California, to Boston, Massachusetts, from the least to most expensive options. 

Priority Mail Flat Rate Envelope
3 days
Priority Mail Small Flat Rate Box
3 days
USPS Retail Ground
7 days
Priority Mail Medium Flat Rate Box
3 days
Priority Mail
3 days
Priority Mail Large Flat Rate Box
3 days
Priority Mail Express 1-Day
1 day

If you can fit that two-pound item in a flat rate envelope, you’ll save $0.50 over the small flat rate box. As you can see, the size of the package affects the price


UPS shipping charges are based on where the package is shipped from, the destination, which service you choose, how much the package weighs, and more. You can estimate your UPS shipping chargesopens in new tab on their site. 

If you’re using UPS, you will have a 150 pound weight limit, and a dimensional limit of 165 inches in total length and girth combined. Special pricing will be applied to packages with a large dimensional weight, and an Over Maximum Limits charge will be added if you go over. Fees do include shipping surcharges such as fuel, import, and export surcharges.

1 to 5 days
3 Day Select
3 days, end of day
2nd Day Air
2 days, end of day
Next Day Air Saver
1 day, end of day
Next Day Air
1 day, 10:30 a.m to 12:00 p.m. 
Next Day Air Early AM
1 day, 8 a.m. to most major cities


With FedEx, the shipping service you choose is the biggest player when it comes to price. However, size and weight also play a role. FedEx also uses the dimensional weight or the actual weight, whichever is the larger number, and you can use their handy price calculatoropens in new tab to find out exactly how much you’ll be charged. 

FedEx lists a variety of weight and dimension limits depending on the service you choose. The largest size limit is for FedEx Express, which has a weight limit of 150 pounds for a package 119 inches long or 165 inches in length plus girth (length + 2 x height + 2 x width). If you go over these limits, you will be hit with an oversize chargeopens in new tab of $105 per package for U.S. Express Package Services and FedEx Ground. FedEx includes fees and surcharges such as shipping to remote areas, shipping dangerous goods, shipping high-value items, and more. A list of surcharges can be found hereopens in new tab

The table below shows the FedEx Retail Rates for shipping a two pound package from San Francisco, California, to Boston, Massachusetts, from the least to most expensive options. 

FedEx Home Delivery
7 days, end of day
FedEx Express Saver
3 days, 8 p.m.
FedEx 2Day
2 days, 8 p.m.
FedEx 2Day
2 days, 12 p.m.
FedEx Standard Overnight
Next day, 8 p.m.
FedEx Priority Overnight
Next day, 12 p.m. 
FedEx First Overnight
Next day, 8 a.m.

DHL eCommerce

DHL eCommerce Solutions is a delivery service for high-volume shippers who need parcels delivered domestically or internationally. Shipping charges are calculated using dimensional weight, and you can get an online quote with their shipping calculatoropens in new tab.  

For businesses, DHL eCommerce offers several service levels for domestic and international shipping. You can ship up to 70 pounds with their domestic shipping services, with a maximum length plus girth of 84 inches. International shipping limits are 66 pounds to Canada and 44 pounds to the rest of the world, with a maximum length plus girth of 118 inches.

With DHL eCommerce you can display real-time duties, taxes, and government fees at checkout for your shoppers. They use an indexed fuel surcharge based on current fuel charges and updated monthly as well as other fees such as shipping dangerous goods, remote area delivery, and more. They also have an overweight charge of $99 per piece and an oversize charge of $70 per piece. 

How to charge for shipping

Shipping can add up, but it doesn’t have to hurt your bottom line. When you know what you have to pay, you can cover that cost in a variety of ways. 

  • Free shipping – Offer your customers free shipping and wrap the cost of shipping into the price of your product or service.  
  • Threshold shipping – Offer free shipping or discounted shipping after customers reach a specified order amount, like $35.
  • Flat rate shipping – If your products typically fit well into one of the USPS flat rate shipping boxes, you can pass that flat rate on to your customers.
  • Shipment-level transit time – Help your customers save time, improve on-time delivery percentiles, and receive extremely reliable delivery estimates using our EasyPost Smartrate API

Whether you cover the cost of shipping by wrapping it into the price of your products or pass the cost on to your customers, you’ll want to get the best rates possible. 

Optimize shipping costs with EasyPost

EasyPost will save you money on your shipping costs. Our API is free for those who ship less than 10,000 packages a month, and if you ship more, you save more – a lot more – by using our API. We deliver the most reliable logistics technology platform for businesses of all sizes, with 99.9% uptime even during peak season shipping.

Take a look at how our solution will save your money: 

  • Discounted shipping – Access our exclusive shipping rates with USPS, FedEx, UPS, DHL, and more. 
  • Create Label tool – Enter your package details into our Create Label tool to easily print labels in minutes. 
  • Shipping API – Compare rates and purchase labels across USPS, FedEx, UPS, DHL, and 100+ more carriers. 
  • <b>SmartRate API</b>Save money and improve on-time delivery metrics with data-backed optimization with every shipment. 
  • Tracking API – Create trackers and receive real-time shipment updates through custom branded tracking pages and webhook notifications. 
  • Address Verification API – Confirm the accuracy of domestic and international addresses to improve deliverability. 
  • Shipping insurance – Protect your packages against damage, loss, or theft across all carriers, service levels, and countries. 
  • Carbon Offset API – Calculate carbon emissions from parcel delivery for every shipment, and purchase offsets to neutralize your carbon footprint.
  • Partner White Label API – White label EasyPost so your customers can sign up and print labels all within your platform.

Sign up today and start saving money on your shipping!