Tie down calculator application provided to you by Ancra International is an aid for determining the minimum strap requirements needed to comply with FMCSA and CCMTA. To calculate the correct number of Ancra tie downs to use, simply select the length of the load, choose bulkhead vs. no bulkhead, choose the appropriate working load limit of the strap, and enter the weight of the cargo. These variables will supply you with the correct number of tie downs to use for a hauling a secure load.