This calculator is an aid for determining the minimum strap quantity needed to comply with FMCSA and CCMTA requirements but is not a substitute for proper training. It is ultimately the responsibility of the driver to insure his load is secure as required by FMCSA Title 49 CFR, section 392.9. This calculator only determines number of tie downs needed using Indirect Attachment points. Only applies using HD Binders if using std 5/16" -3/8" down rate assembly to 5400 lb. WLL. For a list of various commodity types using Direct Attachments, please click the "Commodity Types" button. Direct Attachments are one-half of the working load limit of each associated connector or attachment mechanism used to secure a part of the article of cargo to the vehicle. A vehicle transporting one or more articles of cargo such as, but not limited to, machinery or fabricated structural items (e.g., steel or concrete beams, crane booms, girders, and trusses, etc.) which, because of their design, size, shape, or weight, must be fastened by special methods. However, any article of cargo carried on the vehicle must be securely and adequately fastened to the vehicle.