Shipping Cost Calculator: Uses, Comparing Courier Rates, E-Commerce Checkout Integration, Budgeting, Volumetric Weight & Service Level Selection. Budgeting and Cost Estimation: Finance teams rely on consistent rate data to forecast monthly shipping spend, set product pricing that accounts for freight, and plan for seasonal volume spikes. Anyone shipping packages in the USA can use the DimMath calculator for free — including individual online sellers, small business owners, e-commerce store operators, freight coordinators, warehouse and fulfillment teams, and logistics managers at larger companies.