About ShipMargin

Who runs the site

ShipMargin is run by Adarsh Bora, a software engineer with an interest in technology and ecommerce. Adarsh built the site to help sellers understand the measurements and costs involved in packing, shipping, importing and selling products. The aim is to turn those questions into usable calculators with clear inputs, visible arithmetic and explanations of what the results mean.

Adarsh maintains the site's software and is the contact for corrections and tool suggestions. ShipMargin is an independent project, not a carrier, marketplace, customs authority or professional advisory firm. Software engineering experience does not replace specialist customs, tax or carrier advice.

What we publish

Our tools cover four practical jobs: measuring a parcel, costing an import, planning a freight load and checking a sale. A result should make its inputs and arithmetic inspectable. For example, a lighter box may still cost more to send if its volume takes it into a higher billing band. A low marketplace commission does not make a sale profitable if freight and returns consume the margin.

The calculators are free without registration. They do not connect to your carrier or marketplace account. Where a price depends on that account, the worksheet asks for your quoted fee. Stored reference data has a source and a last-checked date; a page update date does not mean every reference on that page has been reverified.

How a page earns its place

We keep a separate tool when it answers a separate decision. Different names for the same calculation belong on one page. Dimensional, volumetric and chargeable weight now share a worksheet; import duty is part of landed cost; importing for FBA is a mode within the FBA profit planner.

Evidence and review

1. Identify the rule, its jurisdiction, units and effective date.
2. Prefer the carrier, marketplace or authority that publishes the rule. Label secondary sources and unresolved assumptions.
3. Check the arithmetic with reproducible cases, including boundaries and invalid inputs. A correct formula does not prove that an external rate is current.
4. Publish limitations beside the result and link the source. Quarantine uncertain reference tools from search and advertising until the evidence supports publication.

Our methodology documents the calculation sequence. The source register distinguishes primary evidence, corroborated material, secondary summaries and unverified assumptions. We do not claim that an automated test is an expert review or invent professional credentials.

Corrections and maintenance

Use Contact and corrections to report the tool, input scenario, expected result and supporting source. Avoid sending private customer details, credentials or an unredacted invoice. We assess the calculation and its source, update affected pages and record material changes below.

Material changes — 21 September 2026

• Consolidated seven overlapping calculator URLs and updated navigation.
• Corrected USPS native-unit and threshold handling and per-piece billing increments.
• Changed FBA profit planning to use account-specific fee inputs after identifying unreliable automatic size-tier assumptions.
• Moved newly generated scenario links into URL fragments and clarified their privacy limits.
• Added date/input bounds and removed unsupported claims of superiority over other calculators.

Funding and independence

ShipMargin is intended to be supported by advertising. Advertising does not validate a calculation or imply endorsement by Google or a named carrier. Policy, contact, methodology and navigation-only pages do not carry ad inventory.

Adarsh also owns ToolsBay, which is linked as a sister site for document and image tasks. These links are to another project under the same ownership; they are not independent recommendations. Our link policy explains the relationship.

Read the terms of use, accuracy limitations and privacy policy before using or sharing a result.

Publisher contact: adarshsanjaybora@gmail.com. Carrier names and trademarks identify the rules being discussed. Always confirm the payable amount with the party issuing the invoice.