Truckers Per Diem Eligibility Calculator - Version 1.0 Calculate truckers per diem travel expense eligibility for trips. Enter location, purpose, duration, and sleep duration. Find out with the per diem days calculator from Truckers Tax Haven -- where truckers go to save money on their taxes. Free. Truckers Tax Haven has other trucker tax tools, too. Legally pay no state income tax. Legally get more deductions. Legally get more travel expense deductions. Legally pay no sales tax. Company drivers and owner operators. Get trucker tax tips from Truckers Tax Haven at truckerstaxhaven.com.