Don’t worry, “how to measure a box” is not a silly query. Getting packages ready for shipping can be confusing the first time you do it—especially if you’re running a new business and fulfilling your first order.
Knowing exactly how to measure a box is vital for shipping, because carriers and freight companies either charge by the dimensional weight (volume) or the actual weight of a package, so you might be asked its dimensions, volume, or girth. Knowing these numbers can help you secure better shipping rates or determine what kind of shipping is best for your business.
Once you know how to measure a box for shipping and have secured the best rates, this process will become a straightforward part of your business activities—which is why it’s important to get it right from the jump.
How to measure a box
To measure your package, you will need a measuring tool, like a tape measure or ruler, and a pencil and paper to note dimensions.
To measure a box for shipping, you need to determine its outside dimensions.
When measuring your shipping box dimensions, measure its length, width, and height (L x W x H). Measurements should always be listed in this industry-standard order.
To measure the dimensions of a box:
- First, measure the length. This will be the longest side of the box that has a flap.
- Next, measure width. The width side also has a flap but will be shorter than the long side. Turn the box 90 degrees to measure its width.
- Last, measure height. Close the flaps of the box and use a tape measure to calculate the height from top to bottom.
Note: Acceptable manufacturing variance is +/- ⅛ inches.
How to calculate the volume of a box
Knowing the volume of your packages will make things like shipping, warehousing, and distribution easier. Calculating volume is crucial in material and cost optimization.
To calculate the volume of your package for shipping, you will need to multiply length by width by height.
L x W x H = Volume. For example;
- L = 16 inches
- W = 12 inches
- H = 8 inches
16 x 12 x 8 = 1,536 cubic inches (cu).
How to measure the girth of a box
For uniquely shaped packages, such as cylindrical containers used to ship prints or posters, you may need to calculate girth.
To start, you must first determine the package’s width and height. Use a flexible tape measure to find the distance around the package’s widest point. This measurement is its width. Next, measure the longest point from top to bottom. This is its height.
To calculate girth, use this formula: width plus height times two.
Girth = 2 x (width + height)
If we use the example box pictured above, we would add the width (12 inches) to the height (eight inches). This would give us 20. Then we would multiply by two, which gives us its girth, 40 inches.
40 inches = 2 x (12 + 8)
How to keep shipping costs low
With shipping costs rising worldwide, it’s essential to keep an eye on changing shipping rates. These shipping tips for small businesses can help minimize costs:
- Use appropriate containers. Using a large shipping box for a small or lightweight product will cost you. Always choose the smallest box required to ship your product safely. For smaller items, consider lightweight poly mailers instead of boxes.
- Re-use old boxes or “ships in own container” (SIOC) packaging. In some cases, you may be able to simply add a shipping label to your product’s packaging and skip packing it in another box.
- Take advantage of discounts. Check if your ecommerce platform provides any discounted shipping rates. For example, Shopify Shipping helps vendors save up to 88%, with discounts on USPS, UPS, and DHL.
- Measure carefully. Most carriers will charge additional fees for packages weighing more than initially indicated.
Legal and carrier requirements
Different carriers have different requirements. For example, domestic parcels with USPS must measure less than 108 inches in combined length and girth unless they’re being sent with USPS Ground Advantage. In this case, they can measure up to 130 inches in length and girth combined. USPS also has a legal requirement that parcels must be at least three inches high, six inches long, and a quarter inch thick.
Learn more about USPS’s requirements for shipping ground packages here. FedEx has similar stipulations, which you can review here.
Common measuring mistakes
Mistakes happen, especially if you’re measuring multiple shipping boxes simultaneously. Here are some of the most common mistakes:
- Measuring from the inside. This can lead to inaccurate dimensions as you measure the box from the smallest points rather than the biggest ones. To avoid this, always measure boxes from the outside.
- Measuring on an uneven surface. Uneven surfaces can lead to inaccurate measurements. To avoid distortions, measure the box on a flat, stable surface.
- Measuring the smallest points. Not all boxes will be square or rectangular. For uneven or irregularly shaped boxes, measure from the widest and tallest points.
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Measure a box for shipping FAQ
How do you calculate the size of a box?
To calculate a box’s size, measure its length, width, and height. Multiply the three measurements together to get the volume in cubic inches. For example, if a box is 10 inches long, five inches wide, and four inches high, then its volume would be 10 x 5 x 4, which equals 200 cubic inches.
Is there an app to measure a box?
Yes, there are a few apps available to measure boxes. For example, the iPhone and iPad app Measure Kit provides a suite of advanced tools for measuring 3D objects. Other apps, such as AR Measure, use augmented reality and your device’s camera to measure objects in real time.
Can I measure a package without a scale?
You can measure a package without a scale, but it can lead to inaccurate measurements and additional fees if you get it wrong. We strongly recommend using a scale. Home scales will suffice, and most postal offices have scales you can use.
How to calculate package dimensions?
Length, width, height, and girth are all dimensions. Use a tape measure across your item’s length, width, or height to determine these dimensions. To determine girth, add width to height and multiply by two.
