Built for the people who keep things moving.
Supply chains run on a thousand small decisions. Getting the numbers for one of them should be simple.
A useful tool, right when you need it
IronTandem is a collection of free calculators for freight, inventory, and logistics work. Use a tool, check the assumptions, and take the result back to your day. There is no account to create and no trial to cancel.
Clear numbers, visible assumptions
Every calculator includes its formula and an explanation of the model. Carrier contracts, equipment limits, customs treatment, and real operating conditions can vary. The estimates work best when you pair them with your own confirmed data.
How the site stays free
Advertising supports this site. Advertisements are labeled and kept separate from calculator controls and results. Your calculation inputs are processed in your browser; IronTandem does not sell them.
A focused collection
The 72 tools are grouped into freight, inventory, costs, operations, procurement, performance, data analysis, and documents. Some answer a narrow arithmetic question; others compare dated stock, mixed cargo, invoice lines, or return routes. These are planning aids, not connected carrier, ERP, payment, or customs systems. The field guides walk through specific examples and explain why a correct calculation can still need operational review.
Models and corrections
The calculation logic is checked with automated examples, boundary cases, invalid-input cases, and reconciliation tests. Those checks establish consistency with the stated model, not that every model fits every operation. Working calendars, contracts, cost boundaries, and actual equipment can differ. We welcome reproducible corrections through the Contact page; include a small fictional example rather than confidential operating records. No professional credential or endorsement is implied by a calculator result.
Publishing and independence
IronTandem publishes and maintains these tools and field guides under the IronTandem name. Source links identify external references, not an affiliation, certification, or endorsement by a carrier, standards organization, software vendor, or Google. Advertisers do not determine calculator results. Questions about the website, its content, or privacy can be sent privately through our Contact page.