← Parcel dimensional weight calculator
ShipStation is a paid, subscription multi-carrier shipping platform: connect carrier accounts, create a shipment, and it rate-shops live prices across carriers — prices that already fold in each carrier's dimensional-weight charge for that box and destination. Its own published guidance on how dimensional weight and cubic rates work explains the mechanics; the tool itself prices a real shipment once you have one to price.
This calculator answers the question that usually comes before that: while you are still choosing a box, what does this carton actually bill at, how many pounds of that are air, and what is the exact cube and packed height at which the dimensional charge stops applying at all? It does not rate-shop or buy labels, and it needs no account, no carrier connection and no subscription.
| Question | Where to answer it |
|---|---|
| What will a specific carrier actually charge to ship this box to this address today? | ShipStation — that is a real, rate-shopped quote across your connected carrier accounts, which this calculator does not produce. |
| What box size stops me paying the dimensional penalty at all? | This calculator's break-even cube and packed height panel — a target to pack to, not a quote for one shipment. |
| How many pounds of this bill are air, on the box I already have? | This calculator's billable weight panel states the gap directly, before any carrier account is involved. |
| I'm ready to buy a label and want the cheapest carrier for this shipment. | ShipStation — comparing live carrier rates on a real shipment is its job, not this calculator's. |
| Do I need to sign up for anything to check a box size? | This calculator: no. ShipStation is a paid subscription with a free trial, and a real rate needs a connected carrier account. |
Most sellers get use out of both, for different moments: this calculator while deciding on packaging before a run of a SKU ships, and a multi-carrier platform like ShipStation when it is time to actually rate-shop and label a shipment.
No account and no upload here: this is a static page, the arithmetic runs in your browser, and the dimensions you type stay on this device.
They answer different questions at different points in the job. ShipStation is a paid, subscription multi-carrier shipping platform: you connect carrier accounts, create a shipment, and it rate-shops live carrier prices, which already fold in each carrier's dimensional-weight charge for that specific box and destination. Its own published guidance walks through how dimensional weight and cubic rates are calculated. This calculator does not rate-shop, does not buy labels, and does not need a carrier account or a login — it answers the question that usually comes first, while you are still choosing a box: what does this carton bill at, how many pounds of that are air, and what is the exact size that stops the penalty? Decide the box here, then take it to ShipStation (or any carrier account) to actually rate-shop and ship it.
No. This site is not affiliated with, endorsed by, or sponsored by ShipStation or its parent company. ShipStation is a trademark of its owner, named here only to describe what this calculator is and is not.
Not as a standalone question. ShipStation shows you the rate a carrier charges for the box and weight you already entered on a real shipment — it is a rate-shopping and label tool, not a packaging worksheet. This calculator works the ratio backwards from a target: given your actual weight and DIM divisor, it names the exact cube in cubic inches and, where the footprint allows it, the packed height in inches at which the dimensional charge stops applying at all.
For ShipStation, yes — it is a paid subscription product, priced by monthly shipment volume with a free trial and no permanent free plan, and getting a real rate means connecting at least one carrier account. This calculator needs neither: it is a free static page, the arithmetic runs in your browser, and it keeps working with the connection off once it has loaded.