What weight will my parcel be billed at?
Last updated
Outside measurements, at the widest points.
On the scale, packed.
Check your rate card for the service you ship with. It varies by carrier, service and account.
Pick the divisor your carrier uses for this service, or enter your own. Then enter the box and its weight.
- Length, width and height of the packed boxNeeded
- Actual weight on the scaleNeeded
- The divisor your carrier usesNeeded
Confirm the divisor with your carrier: it differs by service and account. Once you know what shipping really costs, set a free shipping threshold that covers it.
No carrier data is used; every figure comes from what you enter. Nothing you type is sent anywhere.
Box size, divisor and billable weight
Dimensional weight is the weight a carrier charges for the space a parcel takes up, and you pay for whichever is greater, its size or its scale weight, so a 3 pound pillow in a 20 by 16 by 8 inch box bills at about 18.4 pounds with a divisor of 139.
No carrier data is used: the divisor is the one you choose, so confirm it with your carrier. To turn a shipping cost into a basket target, see the free shipping threshold calculator.
Three measurements, one weight and one number your carrier chooses. The divisor is the part to confirm, because it changes the answer more than anything you measure.
- Length, width and height
- The outside measurements of the packed box, at the widest points, including any bulge. Measure the box, not the product inside it.
- Divisor
- The figure your carrier uses to turn a volume into a weight. A smaller divisor makes the same box heavier. It varies by carrier, by service and sometimes by account, so pick the preset that matches your rate card or type your own.
- Dimensional weight
- What the box would weigh if the carrier charged by the room it takes on a truck or plane. Light, bulky products are the ones it catches.
- Actual weight
- The packed parcel on a scale, box and filler included.
- Billable weight
- The larger of the two. It is the figure your rate is looked up against, and many carriers round it up to the next whole pound or kilogram first.
- Largest box at actual weight
- The biggest volume this parcel could have and still bill on what it weighs. If your box is larger, a smaller carton saves money on every shipment.
Nudgesmart is available on the Shopify App Store. Browse the template library or see what it costs.
Six parcels, weighed two ways
Illustrative parcels using the preset divisors in the calculator. Confirm your own divisor before quoting any of these to a customer.
| Parcel | Divisor | Dimensional | Actual | Billable | Billed on |
|---|---|---|---|---|---|
| Pillow in a 20 by 16 by 8 inch box | 139 | 18.42 lb | 3 lb | 18.42 lb | Billed on size |
| Cast iron pan, 14 by 12 by 4 inches | 139 | 4.83 lb | 9 lb | 9 lb | Billed on weight |
| Shoes, 13 by 8 by 5 inches, other divisor | 166 | 3.13 lb | 2.5 lb | 3.13 lb | Billed on size |
| Lampshade, 50 by 50 by 40 cm | 5,000 | 20 kg | 2 kg | 20 kg | Billed on size |
| Books, 30 by 25 by 15 cm | 6,000 | 1.88 kg | 6 kg | 6 kg | Billed on weight |
| Same pillow in a 16 by 14 by 6 inch box | 139 | 9.67 lb | 3 lb | 9.67 lb | Billed on size |
Before you trust a dimensional weight figure
Confirm the divisor with your carrier
The presets are common values, not your contract. Carriers set different divisors for ground, express and international services, and negotiated accounts can differ again.
Rounding happens before the rate
Many carriers round each measurement up to a whole unit and then round the result up again. The calculator shows the unrounded figure and the next whole unit; your invoice may round the measurements too.
Size limits and surcharges are separate
Very long or heavy parcels can trigger additional handling or oversize charges that have nothing to do with dimensional weight. Check the size limits for the service you use.
Not every parcel is billed this way
Some services and some small parcels bill on actual weight only. If your rate card has no divisor for a service, dimensional weight may not apply to it.
Bags and soft packs measure differently
A padded mailer or poly bag has no fixed box shape. Measure it filled, at its widest, which is how a carrier would measure it.
Dimensional weight questions
How do I calculate dimensional weight for a parcel?
Measure the packed box, weigh it, and choose the divisor your carrier uses for the service. The calculator returns the dimensional weight, the billable weight and the largest box that would still bill on actual weight. A 20 by 16 by 8 inch box with a divisor of 139 works out at about 18.4 pounds.
Which divisor should I use?
The one on your carrier rate card for the service you ship with. The calculator offers common values for inches and pounds and for centimetres and kilograms, and lets you type any other. If you are not sure, ask your carrier rather than guess.
Why is my shipping charged at more than the parcel weighs?
Because the box is large for its weight, so its dimensional weight is higher than the scale weight and the carrier bills the higher of the two. The pillow in the first worked example weighs 3 pounds and bills at over 18.
How do I lower my dimensional weight?
Use the smallest box the product fits in safely, cut down tall cartons, and switch soft goods to mailers. The last worked example packs the same 3 pound pillow in a smaller box and nearly halves its billable weight.
Does dimensional weight apply to small parcels?
It depends on the carrier and the service. Some apply it to every parcel, others only above a size threshold. Your rate card says which.
Is this calculator tied to a carrier?
No. It uses the divisor you choose and names no carrier. Nothing you enter is sent anywhere.
Packaging decides what a parcel costs. The storefront decides what goes in it.
Nudgesmart works on the storefront side: notification bars and popups from ready-made templates, grouped by industry and campaign type.
