In short
- Multiply packed length × width × height in centimetres, then divide by the service’s factor: 5,000 in the checked DHL Express UK and UPS Netherlands guidance. DPD Poland’s checked guide specifies 6,000 for domestic calculations and 5,000 internationally; compare the result with actual weight before applying the relevant rounding.
- Dimensional weight and volumetric weight describe the same volume-based calculation; the final billable weight can involve further service rules.
- Measure the closed outer package, including any bulge, rather than the product or the box’s internal dimensions.
- Calculate each parcel separately and confirm the rules for your origin, service and contract.
- AirPost is a peer-to-peer fulfilment network: online shops have their orders packed and dropped at a parcel point by verified people near their customers, who earn a fee per parcel from home. No warehouse, no minimum order volume.
A light order can use a surprisingly large weight band when its packaging occupies a lot of space. Before accepting an expensive quote, work out whether the scale or the box is driving it. This practical guide follows the calculation through measuring, rounding and multiple parcels. The existing carrier divisor comparison covers the broader lookup question. Here you can reproduce the arithmetic on your own packed order and see exactly which input changes the result.
Which formula should you put in your calculator?
| Checked official guidance | Formula, centimetres to kilograms | Scope to keep with the formula |
|---|---|---|
| DHL Express UK | (length × width × height) ÷ 5,000 | Express measuring and weighing advice |
| UPS Netherlands | (length × width × height) ÷ 5,000 | Parcel dimensions and weight guidance |
| DPD Poland domestic | (length × width × height) ÷ 6,000 | Polish domestic example in the oversize guide |
| DPD Poland international | (length × width × height) ÷ 5,000 | International rule in that same Polish guide |
Do not leave the service name out of your worksheet. DHL Express and DHL Paket are different products, and another DPD country or booking contract can have different conditions. A rate available through a broker also needs its actual service terms checked. The published factor explains the calculation; it does not establish that a service is available through AirPost or suitable for your goods. Keep the checked source beside the factor so you can revisit it when the route changes.
What exactly do you measure and weigh?
Pack the order fully, close the flaps and put it on a flat surface. Measure the greatest outside extent along each axis. A bowed side counts, as does protection projecting beyond the main box. Weigh the whole shipment with packaging and label. A product listed as 4 kg can become a heavier package when its carton and protection are included. Record the units explicitly: centimetres for this formula and kilograms for the comparison.
For an irregular shape, use the outer rectangular space it occupies. UPS explains this method on its dimensions page. A diagonal object may need a bigger enclosing package than its longest product measurement suggests. Avoid using a supplier’s internal carton specification as your shipping measurement. You can reuse a measurement for an identical packing method, but check it again when you add a second item, change protective material or switch carton supplier.
How does a 55 × 40 × 25 cm box work out?
Assume a closed package measures 55 × 40 × 25 cm and weighs 4.1 kg on the scale. Multiply the dimensions: 55 × 40 × 25 = 55,000 cubic centimetres. At a 5,000 divisor, 55,000 ÷ 5,000 = 11 kg dimensional weight. The volume result is greater than 4.1 kg. Before considering any additional service charges, volume is therefore the important input for the weight comparison.
Using the DPD Poland domestic formula instead gives 55,000 ÷ 6,000 = 9.1667 kg before any applicable rounding. For its international formula, the result returns to 11 kg. This does not tell you which carrier is cheaper: their price bands and other charges can differ. It simply demonstrates why copying a factor from a different service produces the wrong intermediate number, even when all three measurements are correct.
| Illustrative packed box | Actual weight | At divisor 5,000 | At divisor 6,000 |
|---|---|---|---|
| 55 × 40 × 25 cm | 4.1 kg | 11 kg | 9.1667 kg |
| 45 × 35 × 20 cm | 4.1 kg assumed for comparison | 6.3 kg | 5.25 kg |
| 30 × 25 × 20 cm | 4.1 kg assumed for comparison | 3 kg | 2.5 kg |
When do you round the result?
DHL Express UK’s measuring guide states half-kilogram rounding and uses the greater of actual and volumetric weight. Under that stated method, a 6.3 kg volume result becomes 6.5 kg. A result of exactly 6.5 kg already sits on that step. Do not round 6.3 down to 6 because you want the parcel to fit a cheaper band; the rounding rule is part of the calculation.
UPS Netherlands’ support page specifies rounding the dimensional result up to the next half kilogram, while its actual-weight section specifies the next whole kilogram. Thus, for an illustrative 6.2 kg actual weight and a 6.3 kg dimensional result, those instructions produce 7 kg actual and 6.5 kg dimensional; the larger comparison is 7 kg. Check the applicable rate guide if your quote or contract uses a different method.
Keep the unrounded measurements and intermediate result in your record. They help explain what changed if a carrier audits the parcel. The DPD Poland article establishes its divisors and higher-weight comparison, but does not provide a complete rounding schedule for every booking. Do not silently apply UPS rounding to DPD. Use the specific booking terms for that final step, and keep the calculator’s arithmetic separate from the carrier’s accepted billable weight.
Can a smaller box move the shipment into another band?
Repacking the 55 × 40 × 25 cm example into a genuinely suitable 45 × 35 × 20 cm carton changes the volume from 55,000 to 31,500 cubic centimetres. At divisor 5,000, dimensional weight drops from 11 to 6.3 kg before rounding. That is a meaningful weight change, but the price difference must come from two real quotes. There is no universal amount saved per kilogram across carriers.
Check protection before celebrating the smaller result. Fragile goods need enough cushioning and a box able to withstand handling. Compressing the contents into an unsuitable carton can exchange postage cost for damage and replacement work. The 30 × 25 × 20 cm row also illustrates a stopping point: at 3 kg dimensional weight, the assumed 4.1 kg actual weight is already higher. Further shrinking would not reduce the unrounded comparison below actual weight.
How do you calculate a shipment with two parcels?
Calculate each physical parcel independently. Consider one 40 × 30 × 20 cm parcel weighing 2 kg and one 30 × 20 × 20 cm parcel weighing 5 kg. At divisor 5,000, their dimensional weights are 4.8 kg and 2.4 kg. Apply the appropriate comparison and rounding per parcel. Under the checked UPS Netherlands instructions, the first contributes 5 kg and the second 5 kg: 10 kg combined billable weight.
Adding actual weights first would give 7 kg. Adding volumes first would give 36,000 cubic centimetres, or 7.2 kg dimensional weight. Neither aggregate calculation reproduces the per-parcel result because one parcel is volume-limited and the other weight-limited. UPS explicitly says to total individual billable weights for multi-parcel shipments. Still compare an actual two-parcel quote: separate packages can introduce charges that a combined weight does not show.
What else can change the quote after this calculation?
Dimensions can trigger a size restriction or handling charge independently of dimensional weight. Passing the weight comparison does not prove that a parcel fits an accepted point, locker or standard service. Check maximum sides, combined length and girth where relevant, packaging restrictions and the handover method. Then use the accurate measurements to obtain a quote for the actual postcode. The weight formula is one input to booking, rather than the complete pricing model.
If someone else packs your orders, agree the carton and protection method before assigning a shipping format. AirPost’s local fulfilment model lets a shop work with a verified sender near its customers; the sender’s practical capacity still matters. Supply measurements for representative packed orders and ask for a recheck when quantities change. For other cost decisions after packaging is settled, see how to cut shipping costs in Europe.
Frequently asked questions
Are dimensional and volumetric weight different calculations?
They are two names for the volume-based weight calculation. Billable weight is the later result of comparing actual and volume-based weight under the service’s rules.
Do DHL, UPS and DPD all use divisor 5,000?
The checked DHL Express UK and UPS Netherlands guidance uses 5,000. DPD Poland’s checked article uses 6,000 domestically and 5,000 internationally. Confirm the origin, service and contract rather than applying one brand-wide factor.
Do I measure the product or the finished package?
Measure and weigh the finished outer package with all protection included. Use the greatest outside extent on each axis, and the enclosing rectangular dimensions for irregular shapes.
Can I add two boxes together before calculating?
For the checked UPS multi-parcel method, calculate and compare each parcel first, then add individual billable weights. Combining actual weights and volumes first can understate the result.
Does a lower dimensional weight guarantee a cheaper label?
No. Price bands, size limits and additional charges can affect the quote. Compare actual bookings for both suitable packing methods before claiming a saving.
Sources
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