Box size calculator
Enter your product size, add clearance and choose the board. You get the inner dimensions to quote with, an approximate outer size, the volume and the volumetric weight couriers charge by.
Result
Enter length, width and height to see the result.
- Inner dimensions (use these for your quote)
- Approximate outer dimensions
- Inner volume (litres)
- Volumetric weight, divisor 3000
- Volumetric weight, divisor 5000
Approximate values. Flaps, locks, glue areas and inserts change the exact size; your manufacturer works out the final outer size from the dieline.
How the calculation works
- Inner dimensions = product dimensions + the clearance you enter, on both sides of each dimension.
- Approximate outer dimensions = inner dimensions + 2 × board thickness, on length, width and height.
- Inner volume uses the inner dimensions.
- Volumetric weight uses the outer dimensions in centimetres: L × W × H ÷ divisor.
Typical board thickness
The calculator fills in a typical value for each material. Exact thickness varies slightly between board producers.
| Material | Approx. thickness |
|---|---|
| Folding carton board | 0.4–0.7 mm |
| F-flute corrugated | about 0.8 mm |
| E-flute corrugated | about 1.5 mm |
| B-flute corrugated | about 3 mm |
| C-flute corrugated | about 4 mm |
| BC double wall | about 7 mm |
| Rigid box greyboard | 1.5–3 mm |
Volumetric weight in brief
Couriers charge by whichever is greater: the actual weight or the volumetric weight of the parcel. The divisor depends on the carrier and the service. Many domestic couriers in Türkiye use 3000 (the result is called desi); international express services commonly use 5000. Check the divisor in your carrier's terms.
Why the result is approximate
- Tuck flaps, crash-lock bottoms and glue areas add material in some places but not others.
- Double walls, lids and inserts add thickness on specific sides.
- Rigid boxes are wrapped in paper, which adds a little to every side.
Use the inner dimensions when you ask for a quote. If the outer size is the critical limit (a shelf, a shipping carton, a courier size limit), tell us so and we will work from that.
Frequently asked questions
01Should I enter the product size or the inner size?
Either works. Enter your product size and a clearance, or enter the inner dimensions you already know and set the clearance to 0.
02How much clearance should I add?
It depends on the product and the material. As a rule of thumb, a few millimetres per dimension for rigid products, less for soft goods and more when an insert or padding is used.
03Is the outer size exact?
No. It is an estimate based on board thickness. The exact outer size depends on the box style and is calculated from the dieline.
04Which divisor does my courier use?
It varies by carrier and service. The calculator shows the two most common divisors, 3000 and 5000; check your carrier's terms for the one that applies to you.
Have a packaging project in mind?
Send us your dimensions, quantity and artwork — we reply with a detailed quotation and a structural proposal within one business day.