Air freight charges from China can be calculated as a first-weight fee plus charges for each additional weight unit. On this type of parcel shipping plan, the starting fee covers an initial allowance. Any billable weight above that allowance is charged using the additional rate and the route’s rounding rules.
RepDelivery uses this pricing method for relevant shipping services. This guide focuses on those parcel air-shipping and forwarding quotes. Confirm the allowance, billing unit, and delivery coverage for your route before calculating the total. You do not need a public price list to understand how the calculation works.
What Do First Weight and Additional Weight Mean?
“First weight” means the starting weight allowance covered by the initial shipping fee. “Additional weight” means the weight billed after that allowance has been used.
First Weight: The Starting Allowance
A quote should state both the first-weight allowance and its fee. Knowing only the fee leaves you unable to calculate where additional charges begin.
If your billable weight stays within the starting allowance, the first-weight fee applies under that plan. A lighter package does not necessarily receive a lower fee.
Additional Weight: The Extra Billing Units
Once the shipment exceeds the starting allowance, additional-weight charges apply according to the quoted unit.
Check whether the extra rate is per kilogram, per half-kilogram, or another increment. Also ask how a partly used unit is treated. Do not assume that every route follows the same rule.
| Quote term | What it tells you |
|---|---|
| First-weight allowance | Weight covered by the initial fee |
| First-weight fee | Starting charge under the plan |
| Additional-weight unit | Size of each extra billing increment |
| Additional-weight rate | Fee for each extra unit |
| Rounding rule | How partial units are billed |
| Chargeable weight | Weight used to calculate the charge |
How to Calculate Air Freight Charges from China
For a quote with one additional-weight rate, the basic calculation is:
Base shipping charge = first-weight fee + number of additional-weight units × fee per additional unit
If no additional units are needed, the base shipping charge is the first-weight fee. Any separately quoted services or surcharges must then be added to find the full payable amount.
Step 1: Confirm the Weight Used for Billing
Start with the weight accepted for billing on the selected route. Do not use the product’s net weight unless the provider specifically confirms that basis.
Ask whether the calculation uses packed gross weight, a comparison with volumetric weight, or another stated rule. For several cartons, confirm whether billing is calculated separately or across the shipment.
Step 2: Subtract the First-Weight Allowance
If the billable weight exceeds the allowance, subtract the allowance to find the remaining weight.
The starting fee already covers the first-weight portion. You should not apply the additional-weight rate to the whole shipment unless the quotation expressly describes a different pricing method.
If the billable weight is at or below the allowance, use zero additional units. Do not calculate a negative extra charge.
Step 3: Apply the Additional Unit and Rounding Rule
Divide the remaining weight by the additional-weight unit. Then apply the agreed rule for partial units.
If the route bills every started unit as a full unit, round the result up. If it allows proportional billing, use that method instead. This distinction can change air freight charges from China even when the listed rates look similar.
Step 4: Add Only the Applicable Extra Charges
Check the quotation for services outside the base charge, such as optional repacking or a stated delivery surcharge. Confirm what is already included so that the same service is not counted twice.
First-Weight and Additional-Weight Calculation Examples
The examples below use a hypothetical allowance of 1 kg, an additional unit of 0.5 kg, and rounding up for each started additional unit. These are teaching assumptions, not RepDelivery’s published route rules.
All weights in the table are assumed to be chargeable weights after any applicable weight assessment.
| Chargeable weight | Weight above the allowance | Additional units | Base charge |
|---|---|---|---|
| 0.8 kg | None | 0 | First-weight fee |
| 1.0 kg | None | 0 | First-weight fee |
| 1.3 kg | 0.3 kg | 1 | First-weight fee + 1 extra unit |
| 1.5 kg | 0.5 kg | 1 | First-weight fee + 1 extra unit |
| 1.6 kg | 0.6 kg | 2 | First-weight fee + 2 extra units |
The important point is the billing boundary. Under these example rules, moving from 1.3 kg to 1.5 kg adds no further unit. Moving from 1.5 kg to 1.6 kg does.
Before approving shipment, ask for the final chargeable weight and the number of additional units. Those two figures make the calculation much easier to check.
Why Can Small Parcels Cost More per Kilogram?
A small parcel’s starting fee is spread across relatively little weight. Adding weight may spread that initial fee over more goods, although the total bill can still rise.
You can compare shipments using:
Average base shipping cost per kg = base shipping charge ÷ chargeable weight
Also, a falling average is not guaranteed. It depends on the relationship between the starting fee and the additional rate, as well as rounding and any changes in service.
For a small order, the useful question is: “What is the total charge for my packed goods?” Looking only at an advertised extra-weight rate can hide the starting charge.
Which Weight Determines the First and Additional Charges?
The scale reading and the billable weight may differ. Packaging adds physical weight, while large boxes may also affect volume-based billing.
IATA’s explanation of air cargo tariffs and rules describes how weight, volume, and additional fees can influence air cargo pricing. That general guidance does not establish RepDelivery’s first-weight allowance or rounding rules.
For your shipment, request confirmation of:
- Whether packed gross weight or volumetric weight affects billing.
- The applicable volumetric formula, if used.
- Whether each carton is assessed separately.
- When weight rounding takes place.
- Whether the quote will be updated after final packing.
For broader background on weight and other pricing factors, see our air freight cost from China guide.
Does Combining Parcels Reduce First-Weight Charges?
Combining parcels may reduce repeated starting charges if the selected service bills the combined package as one shipment. It is not an automatic saving.
First establish what the provider means by one billable shipment. Several cartons sent under one order may still be rated separately.
Compare Separate Shipping with a Combined Shipment
Request two calculations using the same destination and service level:
- The total for sending the parcels separately.
- The total after receiving, combining, and repacking them.
Include any additional warehouse work in the comparison. Use the proposed combined dimensions and weight, not just the sum of the product weights.
A combined package might reduce repeated initial fees but become bulkier, require stronger packing, or fall under a different pricing plan.
Keep the Delivery Deadline in View
Waiting for another supplier can delay goods that are ready now. If those goods are needed urgently, paying for separate shipping may be the more practical choice.
How to Compare Two First-Weight Shipping Quotes
To compare air freight charges from China, calculate both quotes for the same packed shipment and delivery scope. A lower first-weight fee can be offset by a higher additional rate or a smaller starting allowance.
Compare the full amount at your expected billable weight. If packing is still being finalized, also ask for the total at the next billing boundary. This shows whether a small weight change could affect your choice.
| Check | Question to ask |
|---|---|
| Starting allowance | What weight does the first fee cover? |
| Additional rate | Is this price per kg or per another unit? |
| Partial units | How is an incomplete extra unit charged? |
| Multiple cartons | Does the starting fee apply per carton or per shipment? |
| Weight assessment | Which weight and dimensions will you use? |
| Service coverage | Which handling and delivery services are included? |
| Extra costs | What could be charged separately? |
| Quote validity | How long is the quotation valid? |
Ask separately whether any quoted tax-paid service includes the relevant duties, taxes, clearance, and final delivery for your destination. A first-weight and additional-weight price alone does not answer those questions.
How to Request a Useful Quote from RepDelivery
Send your product description, destination country and postcode, parcel count, packed weight, and carton dimensions. Mention whether goods come from one supplier or several and whether you need repacking.
Flag batteries, liquids, fragrances, or other goods that may need a route check. A quotation for ordinary goods should not be assumed to apply to every product.
You can use this request:
“Please confirm the first-weight allowance and fee, the additional-weight unit and rate, the rounding rule, and the chargeable-weight basis for this shipment. Please also list included services and any separate charges.”
If the goods are not packed yet, say which measurements are estimates. For the full information checklist, use our air freight quote from China guide.
Frequently Asked Questions
Is First-Weight Pricing Used for All Air Freight?
No. This guide applies to parcel air-shipping or forwarding services quoted on a first-weight and additional-weight basis. Other cargo services may use weight brackets, minimum charges, or other rate structures.
Is the First Weight Always One Kilogram?
No. The starting allowance must be shown in the quotation. The 1 kg allowance in this article is only an example and should not be used to estimate an actual booking.
Is Additional Weight the Same as Overweight Cargo?
No. Additional weight means weight above the initial pricing allowance. It does not by itself mean the package exceeds a carrier’s size or weight limit.
Does Repacking Always Lower the Charge?
No. It may help if it reduces the billable weight enough to cross a charging boundary. Protective materials, repacking fees, and route rules can affect the result.
Does the Additional-Weight Rate Apply to the Whole Parcel?
Under the plan explained here, it applies only to units above the first-weight allowance. Multiplying the entire parcel weight by the additional rate leaves out the starting fee and can produce the wrong total.
Will Two Parcels Be Charged Two First-Weight Fees?
That depends on whether the service rates them separately or as one combined shipment. Ask for the billing basis before dispatch. One customer order or one payment does not necessarily mean one starting fee.
Confirm the Billing Rules Before You Book
Air freight charges from China are easier to understand when the quote clearly states the starting allowance, additional unit, rate, and rounding method.
Before approval, request a breakdown showing the chargeable weight, starting fee, number of extra units, additional charges, and any separately billed services. The figures should add up to the quoted total.
Planning a small shipment? Send RepDelivery your product details, destination postcode, carton count, packed weights, and dimensions. For air freight from China, request the applicable first-weight and additional-weight breakdown. If you have several supplier parcels, ask whether separate or combined billing suits your shipment.