See the billing basis
Compare scale, dimensional and billable weight without decoding carrier language.
Free shipping audit
Shipping calculator for online sellers
Know the weight you will actually pay for. Enter the package size and scale weight to see billable weight, wasted space and margin, with 2026 UPS, FedEx and USPS rules built in.
✓ No sign-up✓ Metric + imperial✓ Runs in your browser
Batch audit
Paste a product or package list.
Use six columns: sku,length,width,height,weight,quantity. Everything stays on this device.
◆ CSV contents are processed locally and are never uploaded.
Valid rows0
DIM-controlled0
Total air weight0 lb
| SKU | Scale | DIM | Billable | Signal |
|---|---|---|---|---|
| Paste CSV data to see the audit. | ||||
New · box optimizer
Compare my boxes →Which carton costs less after shipping?
Compare every available box by fit, billable weight and estimated monthly savings.
Why sellers keep it
One quick check before every label.
Use the answer, share it, and get back to shipping.
Protect the order margin
Add the sale and cost details to see whether shipping quietly turned profit into loss.
Share the evidence
Copy the audit, download a clean CSV or send a privacy-safe calculation link.