Shipping Cost Calculator
Dimensional weight against actual weight, which one is billing you, and what a smaller box would save, because carriers charge for space rather than mass.
Box 50.0 × 40.0 × 40.0 cm
Volume 80,000 cm³
Actual weight 2.00 kg
Dimensional weight 16.00 kg
divisor used metric, 5000, the older standard
the sum 50.0 × 40.0 × 40.0 ÷ 5,000
Billable weight 16.00 kg
which one the dimensional weight, because the box is light for its size
paying for 14.00 kg of air, 700% more than it weighs
rounded up 16.00 kg, as most carriers do
Other things a carrier measures
longest side 50.0 cm
length plus girth 210.0 cm
why oversize surcharges are triggered by these, not by weight
Cost
base rate $6.40
16.00 kg at $1.85 $29.60
surcharges $2.20
a parcel $38.20
if it billed by actual weight $12.30
the dimensional premium $25.90, 210.6% more
What a smaller box would do
10% off each side 12.00 kg billable, $7.40 saved
20% off each side 8.50 kg billable, $13.88 saved
30% off each side 5.50 kg billable, $19.43 saved
The dimensional weight is billing: 16.00 kg against an actual 2.00 kg,
so you are paying for 14.00 kg of air. Carriers charge by the greater of
the two because space on a vehicle is the scarce thing, not mass.
The divisor is the whole calculation and it is negotiable. metric, 5000,
the older standard is used here; a 4000 divisor makes the same box 25
percent heavier to ship than a 5000 one. Check the divisor on your own
contract, because the published ones have been tightened repeatedly and
a negotiated rate often has its own.
Reducing the box is usually the largest available saving and it needs
nobody's agreement. Ten percent off each side is a 27 percent volume
reduction, which comes straight off the dimensional weight, and
right-sized packaging also reduces damage and the void fill you buy.
Carriers round up, usually to the next half or whole unit, and they
measure the outside of the box including any bulges. A box that measures
30.2 cm bills as 31, so designing to just under a round number is worth
doing deliberately.
Oversize and additional-handling surcharges are triggered by dimensions
rather than weight: a longest side over about 120 cm, or length plus
girth over about 270, and those charges are often larger than the
freight itself. Both figures are above.
Free shipping is a pricing decision, not a logistics one. The cost does
not disappear; it moves into the product price or the margin, and the
useful question is whether the conversion lift pays for it, which the
average order value tool on this site helps with.
Fuel surcharges are percentages of the base rate and they move monthly,
so a quoted rate from three months ago is not the rate. Anything
comparing carriers needs the surcharge as it is today, applied to both.
These figures are arithmetic on the rates you supply. Real carrier
pricing has zone tables, service levels, residential and remote-area
fees, and a negotiated discount that varies by lane, and no calculator
reproduces a rate card.
Output is valid and updates as you type.
Fix the highlighted fields to update the output.
A box of cushions weighing two kilograms costs $38.20 to ship. The same weight in a small dense parcel costs $12.30. Nothing about the contents changed; the box did.
Carriers bill the greater of the actual weight and the dimensional weight, which is the volume divided by a divisor they publish. A 50 × 40 × 40 cm carton on a 5000 divisor is 16 kg of billable weight, so two kilograms of cushions pays for fourteen kilograms of air. Space on a vehicle is the scarce thing, not mass.
The first useful output is which of the two weights is billing. The second is what a smaller box saves, because that is usually the largest saving available and it needs nobody’s agreement.
How to use
- Put in the outside dimensions of the packed box and its real weight.
- Pick the divisor from your own contract, which may not be any published figure.
- Add the rates to see the money, and read the smaller-box rows.
Example
Box 50.0 × 40.0 × 40.0 cm
Actual weight 2.00 kg
Dimensional weight 16.00 kg
divisor used metric, 5000, the older standard
the sum 50.0 × 40.0 × 40.0 ÷ 5,000
Billable weight 16.00 kg
which one the dimensional weight, because the box is light for its size
paying for 14.00 kg of air, 700% more than it weighs
Cost
base rate $6.40
16.00 kg at $1.85 $29.60
surcharges $2.20
a parcel $38.20
if it billed by actual weight $12.30
the dimensional premium $25.90, 210.6% more
What a smaller box would do
10% off each side 12.00 kg billable, $7.40 saved
20% off each side 8.50 kg billable, $13.88 saved
30% off each side 5.50 kg billable, $19.43 savedTen percent off each side is a 27 percent volume reduction, and it comes straight off the bill.
Pitfalls
The divisor is the whole calculation. A 4000 divisor makes the same box 25 percent heavier to ship than a 5000 one. Published divisors have been tightened repeatedly, and a negotiated contract often has its own, so read yours rather than trusting a default.
Carriers measure the outside, including bulges. A box that measures 30.2 cm bills as 31, because they round up. Designing packaging to sit just under a round number is worth doing deliberately.
Oversize surcharges are triggered by dimensions, not weight. A longest side over about 120 cm, or length plus girth over about 270, and the surcharge is often larger than the freight. Both measurements are in the output.
Right-sizing the box saves twice. Less dimensional weight and less damage, because a product that cannot move inside its box arrives intact. It also cuts the void fill you buy.
Fuel surcharges move monthly. They are a percentage of the base rate, so a quote from three months ago is not the rate. Any comparison between carriers needs today’s surcharge applied to both.
Free shipping is a pricing decision. The cost does not vanish; it moves into the price or the margin. The question is whether the conversion lift pays for it, which is a different calculation from this one.
Multi-box orders are billed per box. Consolidating two parcels into one usually costs less than the sum, and sometimes more if consolidating pushes the single box past an oversize threshold.
Compatibility
Arithmetic in the browser: nothing is uploaded and nothing is stored.
The dimensional weight is volume divided by the divisor, and the billable weight is the greater of that and the actual weight, rounded up to the next half unit, which is what most carriers do. The units follow the divisor: centimetres and kilograms for the metric ones, inches and pounds for the imperial.
Length plus girth is calculated as twice the width plus twice the height plus the longest side, which is the standard formula, and it is printed because oversize thresholds use it.
Real carrier pricing has zone tables, service levels, residential and remote-area fees, and negotiated discounts that vary by lane. This computes the weight properly and applies the rates you give it; it is not a rate card.