How long does priority mail cubic take

USPS Priority Mail Cubic pricing can be one of the most cost-effective options for e-commerce businesses. But, what is it exactly, and how do you qualify for it? Check out this cheat sheet to learn more now. 

What is USPS Priority Mail Cubic Pricing?

USPS Cubic pricing is a lesser-known part of USPS’s Priority Mail program that is generally only accessible by businesses that ship more than 50,000 packages a year. USPS Cubic pricing rates are determined by package size and distance traveled as opposed to weight. So, for companies that ship smaller, heavier items, it can be a great option.

How Do You Qualify for USPS Priority Mail Cubic Pricing? 

As mentioned above, normally you’d have to be a large company that ships at least 50,000 packages per year, but if you use Shippo, you will not only qualify, but can save up to 89% on USPS Priority Mail Cubic pricing. That’s because Shippo is able to combine all of its package volume to allow users to take advantage of significant savings without needing to meet the traditional volume of shipping required.

Are There Package Requirements?

Packages must:

  • Weigh less than 20 pounds
  • Measure up to 0.5 in cubic feet
  • Have sides that are less than 18 inches; if a side is too close to this measurement, it might be disqualified
  • Fit the quantity requirements of 50,000+ packages shipped annually, unless using Shippo

Steps to calculate your package’s cubic feet include:

  • Measuring its length, width, and height
  • Rounding down to the nearest quarter inch (if applicable, and already under 18 inches)
  • Multiply the three measurements (length, width, and height) and divide by 1,728

This is your package’s cubic feet size. Is it less than 0.5? If so, then it passes that particular requirement for USPS Cubic rates. 

Here’s an example. Say you have a package that is 8 x 5 x 6.6 inches in size. First, you’d round down to the nearest quarter inch for any sides that are over; so it would be 8 x 5 x 6.5 inches. Then, you’d multiply those numbers, bringing it to 260. Now, divide by 1,728. The result? A cubic feet value of 0.150—which means this package qualifies. 

Although these packages are often square or rectangular in shape, they don’t have to be, as long as they meet size requirements. They can, in fact, be envelopes. In that case, you’ll need to measure the item before putting it into an envelope. The longest dimension (meaning length, width, or height) can’t be more than 18 inches, with the smallest one needing to be two inches or smaller. When you add up the longest dimension and the next longest one, the sum can’t be more than 36 inches. Note: tubes or rolls will not qualify. 

USPS Cubic Rates and Savings

There are five different pricing tiers in this shipping program. To figure out your rate, pick the appropriate tier:

  • 0.1: up to .10 cubic feet
  • 0.2: more than .10 and up to .20 cubic feet
  • 0.3: more than .20 and up to .30 cubic feet
  • 0.4: more than .30 and up to .40 cubic feet
  • 0.5: more than .40 and up to .50 cubic feet

Using that info, you can find your USPS Cubic rate by using these charts. 

Now, compare that rate to what you’ve been paying to find your cost savings on this package. Estimate how many packages of each pricing tier you’ll likely ship during a year, and you’ll have a strong sense of your potential annual savings. 

Examples of Items That Benefit from USPS Cubic Pricing

If your business, for example, provides customers with subscription boxes that contain relatively small but often heavy items, USPS Priority Mail Cubic pricing could be a great option. Or, let’s say that you sell antique reference books, paperweights, hand weights for exercising, personalized stones for patios (under 20 pounds, of course), and you get the idea. Small. Heavy. Traditionally expensive to ship, but not with cubic pricing.

Benefits for Businesses of All Sizes

We see it all the time—big companies leveraging volume discounts that smaller businesses simply can’t take advantage of. But with Shippo, the USPS Priority Mail Cubic pricing program levels the playing field, allowing e-commerce companies of all sizes to benefit from some of the lowest shipping rates available for packages that fit the size parameters. Plus, delivery is fast, too—generally within one to three days in the USA.  

Have you ever heard of the term “Priority Mail Cubic?” That’s what we thought—most people haven’t! Priority Mail Cubic is one of the US Postal Service’s best kept secrets, and we’re about to let you in on it. Think of it a bit like “Animal Style” for In-N-Out Burger, except you’ll be saving tons of money on shipping packages instead of ordering secret sauce.

Table of Contents

  • What is Priority Mail Cubic?
  • How Much Does Priority Mail Cubic Cost?
  • Priority Mail Cubic in Action
  • You Can Also Use Cubic for a Poly Mailer or Padded Envelope

What is Priority Mail Cubic?

We’re glad you asked! To put it simply: Priority Mail Cubic (or “Cubic” for short) is a secret service you won’t find at the Post Office, but it’s the cheapest and fastest way to ship small packages. Priority Mail Cubic isn’t priced based on weight—instead, the outer dimensions of your package determine the price. Like all Priority Mail services, Priority Mail Cubic delivery occurs between 1-3 business days, it comes with free package tracking, and even includes $100 of insurance at no extra cost. If you’re thinking that shipping Priority Mail Cubic sounds like a total no-brainer right about now, you’re absolutely correct. However, it does have some restrictions, which we’ve outlined below:

  • No one dimension on your package can exceed 18 inches
  • Total weight of your package cannot exceed 20 pounds
  • Total volume of your package must not exceed 0.5 cubic feet

If your package meets the above requirements, it’s off to the races!

Pro Tip: Priority Mail Cubic is the best for sending small, heavier items. Therefore, this is the best mail class for situations such as shipping honey and jams, shipping coffee, shipping candles and more.

How Much Does Priority Mail Cubic Cost?

Depending on the size of your package, there are five different cubic pricing tiers it will fall into. Pricing tiers are determined by cubic feet, and we’ve included those tiers in the chart below.

Cubic Feet
Up to, not over0-150 miles
L, 1 & 2150-300 miles
Zone 3300-600 miles
Zone 4600-1000 miles
Zone 51000-1400 miles
Zone 61400-1800 miles
Zone 71800+ miles
Zone 8All US Territories
Zone 90.1$7.02$7.35$7.56
$7.80$7.98$8.15$8.42$11.400.2$7.46$7.80$8.02$8.71$9.00$9.22$9.56$13.150.3$8.04$8.26$8.55$9.65$10.98$11.58$12.29$19.120.4$8.21$8.57$8.93$10.31$12.78$14.02$16.02$24.280.5$8.34$8.84$9.42$11.15$14.98$16.89$19.24$29.88

To calculate which cubic pricing tier your package falls into, follow these steps:

  1. Measure the length, width, and height of your package. When measuring your package, always round down to the nearest quarter inch. For example, if your package height is 6.3 inches, round it down to 6.25.
  2. Once you’ve got your dimensions, multiply them all together (Height x Width x Length). Next, take that number and divide it by 1728.
  3. The resulting decimal is the size of your package in cubic feet. Use the chart above to determine the pricing tier, always rounding up fractional results to the next tier (for example: if your package is 0.24 cubic feet, it will fall into the 0.3 tier).

Not in the mood to do the math? You can use this handy Priority Mail Cubic Calculator. Just type in your dimensions, and it will automatically tell you which pricing tier your package falls into. The calculator also makes suggestions to help you get the most bang for your buck on your package size!

Pro Tip: Be smart with your package dimensions! If the contents of your package allow for it, it’s a good idea to plan your package to fit within the smallest tier possible. The best part is: since Cubic pricing isn’t based on weight, you can stuff your package to the brim! Just make sure the total weight doesn’t exceed 20 pounds. Doing this can drastically lower your cost of shipping. In fact, your shipping costs will be so low that your business can offer free shipping, which is a tried and true way to build customer loyalty. Makes sense, right? Don’t worry…your secret’s safe with us.

Priority Mail Cubic in Action

Want to see how Priority Mail Cubic stacks up against the competition? Let’s try a simple exercise. Imagine you have an 8x8x8 box that weighs 10 pounds, and you’d like to ship it from Los Angeles to Denver. The distance between those cities is approximately 1,016 miles, which puts your shipping rate in Zone 6 (you can see that in the chart above). If you ship the box USPS Priority Mail with a 3-day transit time, that price at the 2020 USPS Commercial Pricing rates would come to $26.67.

Using Cubic Shipping, that same package (in the .3 cubic tier) would cost only $10.98 for Zone 6. That’s about 41% less!

Cubic also beats UPS and FedEx Ground prices by a landslide. For the same 10-pound package, FedEx Ground (4-day transit time) would cost $19.00. After applying residential delivery surcharges, the UPS rate would be similar. Applicable fuel surcharges would also apply to both UPS and FedEx, potentially pushing both costs up to $20 or $21. Considering the $10.98 rate you you can get with Priority Mail Cubic, there’s simply no comparison.

You Can Also Use Cubic for a Poly Mailer or Padded Envelope

Believe it or not, Priority Mail Cubic isn’t just for boxes! You can also use USPS Cubic for a soft-pack or padded envelope. This process is known as “box in a bag” shipping. Just like with regular boxes, you’ll need to make sure that your sides aren’t over 18 inches in each direction. Also, the total weight of the envelope can’t exceed 20 pounds.

Here’s the thing, though. You’ll need to measure the envelope’s dimensions before you put anything in it. Only measure the length and the width of the envelope (since envelopes technically don’t have a height dimension). When you add the length and width together to get the total inches, that number will determine which pricing tier your envelope belongs to. The total number of inches cannot exceed 36.

Pro Tip: You can’t use expandable or pleated envelopes! If your envelope expands, it technically has a third dimension (height), so you’ll need to measure it the same way you would a box: length + width + height.

Ready to Start Saving Money on Shipping?

In the words of the wise DJ Khaled, “They don’t want you to know about Priority Mail Cubic!” But guess what? We want you to know. Shipping Priority Mail Cubic is simply one of the cheapest ways to ship with USPS, and you can start right now. There are several shipping software options out that sell Priority Mail Cubic postage at discounted rates. However, they’re all a bit different, and some are certainly better than others. Before your start shipping, we suggest doing research to see which one best fits your needs!

Is Priority Mail cubic faster?

Simply put, Priority Mail Cubic is the cheapest and fastest way to send small, heavy packages under 20 pounds with USPS. Anyone who takes advantage of Priority Mail Cubic enjoys better shipping rates than they would with any other service.

What is Priority Mail cubic USPS?

Priority Mail® Cubic is a special rate or sub-service of Priority Mail® for smaller packages where a mailer pays based on the size of the mail piece instead of the weight. It has a maximum weight of 20 pounds and the size can be no bigger than . 5 cubic feet.

How long do priority Mail boxes take?

1-3 Business Days1 & Flat Rate Pricing Priority Mail® service includes tracking and delivery in 1-3 business days1.

Is Priority Mail Cubic the same as flat rate?

USPS Priority Cubic doesn't provide free boxes, but it does deliver significantly better rates than Priority Mail flat rate for small, heavy packages.