Calculator · sample rates, editable · 2026-11-08
Shipping estimator: first weight, continued weight, and volumetric weight
Picture the usual situation. Three pairs of shoes and two hoodies are sitting in a warehouse overseas, the consolidated box measures 46 x 34 x 28 cm, and the freight number someone quoted you is a single figure with no explanation attached. This estimator takes that figure apart. You enter the packed box size and a real scale weight, the tool computes actual weight and volumetric weight, keeps the larger of the two, and applies a sample rate table with a first-weight charge and a continued-weight charge. Everything you see is a planning estimate, not a checkout price, because carriers price by route, by service level, and by the day.
Fill the fields and the result appears here.
How the number is built
Sample rates, editable in the tool, as of 2026-11-08. Economy line: first 0.5 kg = $9.50, then $3.60 for every additional 0.5 kg. Express line: first 0.5 kg = $14.00, then $5.80 for every additional 0.5 kg. Surface line: first 1.0 kg = $7.20, then $2.40 for every additional 0.5 kg. Handling is $2.00 per parcel and $1.50 per extra item inside a consolidated box. Volumetric weight = length x width x height / divisor. Chargeable weight = the larger of actual and volumetric. These are our own sample numbers built for planning, not a quote from oopbuy.com, spreadsheetkakobuy2027.com, or any carrier.
What each field is asking for
- Box length in centimetres. Measure the outside of the packed box, including tape and corners, not the item inside it.
- Box width in centimetres, measured across the widest point of the closed box.
- Box height in centimetres, from the bottom face to the top face while the box is standing as it will be shipped.
- Actual weight in kilograms from a luggage or kitchen scale. If your scale only reads pounds, divide by 2.2046 before typing it in.
- Divisor: 6000 for most economy lines, 5000 for some express lines. Use the one your chosen line publishes; the figure changes the answer by roughly 17 percent in each direction.
- Shipping line preset: economy, express, or the slow surface option. Each preset carries a different sample rate pair.
- Consolidation toggle. On means several warehouse parcels are merged into one box and share a single first-weight charge.
- Optional declared value in USD. It only raises a duty flag on the result line; it never changes the freight arithmetic.
What you get back
A single panel with five numbers: volumetric weight in kilograms, chargeable weight in kilograms (the larger of actual and volumetric), the first-weight charge, the continued-weight charge, and a total in USD with a CNY equivalent at 7.20 CNY per USD. Under the total you get one line naming which weight won, and one line showing how much money the box size alone added compared with a hypothetical box of the same volume at the denser packing.
The method
Why the arithmetic works this way
If you understand the mechanics you can sanity-check any quote, including ours.
Why our number and the real quote will differ
A shipping quote is a chain of decisions, and this estimator only sees the last link. The carrier prices by the lane it actually flies or sails, by whether your destination is a residential or commercial address, by fuel surcharges that move weekly, and by a peak-season multiplier that appears without warning between October and January. Our table is a single averaged pair of numbers across all of that. Treat the result as a sanity check. If your real quote is double the estimate, the reason is usually a remote-area surcharge, a battery or liquid restriction, or a dimensional scan that came in larger than the box you measured. If it is half, you probably picked a slower line than the preset you used here.
Volumetric weight is where the surprises live
Most first-time buyers assume the scale weight rules. On light and bulky goods it does not. A box of hoodies can weigh 2.4 kg on a scale and still bill at 6 kg because the carrier measures the space it occupies. The break-even is easy to feel: at a divisor of 6000, one kilogram of volumetric weight equals 6000 cubic centimetres, which is a box around 18 x 18 x 18 cm. Squeeze your hoodies into a smaller box and you pay for air you are not shipping. Our estimator shows both weights on the same screen for that reason, and the difference between them is the amount you could recover by repacking.
What we cannot see from a web page
We do not know your account level, so we cannot know whether you get a discounted rate card. We do not know the exact line the warehouse will offer you on the day the parcel is ready, because line availability changes and some lanes stop accepting certain goods. We do not know the exchange rate that will be used if your agent bills in a currency other than the one you funded the account with. And we cannot know whether the box the warehouse packs matches the box you measured at home, because the warehouse packs what fits once everything is consolidated. Each of those gaps can move the final number by a few dollars. The estimator is honest about its inputs, so at least you can see which of them you are guessing at.
Consolidation trades one charge for another
Merging parcels is usually cheaper per item, because the first-weight charge is charged once instead of once per parcel, and our sample handling fee falls the same way. But consolidation also adds volume. Two pairs of shoes that each ship in a 33 x 22 x 13 cm box can be packed together into a box that is not twice that size, but it is often more than 1.7 times it, and the volumetric weight follows the outer box, not the sum of the inner ones. The estimator makes the trade visible: compare the merge result against the sum of the separate results. When the merged volumetric weight climbs past the actual weight, the saving from the shared first weight can still win, but only if the box is packed tight.
Worked example
Numbers you can check against the form
Run one of these rows through the fields above and the output should match.
| Parcel | Actual | Volumetric (÷6000) | Chargeable | Economy | Standard | Express |
|---|---|---|---|---|---|---|
| Single tee, bagged | 0.25 kg | 0.14 kg | 0.25 kg | $8.97 | $10.50 | $17.73 |
| Sneakers, no box | 0.85 kg | 0.60 kg | 0.85 kg | $11.38 | $13.44 | $23.16 |
| Sneakers, with box | 1.10 kg | 1.85 kg | 1.85 kg | $18.27 | $21.84 | $38.70 |
| Hoodie + 2 tees | 1.40 kg | 0.95 kg | 1.40 kg | $15.17 | $18.06 | $31.71 |
Common questions
Questions about this calculator
Is this the price oopbuy.com or Spreadsheet KakoBuy would charge me?
No. oopbuy.sbs is an independent third-party guide and we are not affiliated with oopbuy.com, Spreadsheet KakoBuy, or any carrier. The rates on this page are our own sample numbers. They exist so you can tell which part of a quote moves the total, not so you can predict a bill.
Which divisor should I use, 6000 or 5000?
Use whatever the line you selected publishes. A smaller divisor produces a larger volumetric weight, so 5000 is the harsher of the two and is common on express services that charge by space. If you cannot find the figure, run both and keep the worse one as your budget number.
Should I remove shoe boxes?
Almost always yes for shoes. A single shoe box runs about 0.35 to 0.60 kg and usually adds several centimetres in every direction, so removing it cuts both weights at once. The tradeoff is protection and resale value. Ask for the shoes to be wrapped in bubble film and note that you accept the risk.
Why does the estimate jump when I change only the height?
Because volumetric weight multiplies all three dimensions. Add two centimetres to the height of a 46 x 34 cm box and you add 46 x 34 x 2 = 3128 cubic centimetres, which is over half a kilogram of billable volumetric weight at a divisor of 6000. Height is the dimension most often overfilled by packing material, so it is also the easiest one to reduce.
Related searches
- shipping estimator
- agent shipping cost
- first weight and continued weight
- volumetric weight
- parcel consolidation
- oopbuy shipping calculator
- oopbuy spreadsheet
- oopbuy spreadsheets
Now put a real row through it
The calculator tells you what a parcel costs. The catalogue tells you what goes in it.
- 1,711 rows in the current snapshot
- Both currencies on every row
- Filter by brand or category before you commit
Sponsored outbound link. Independent guide, sample rates.