Truckers Per Diem Days Calculator - Version 1.0 Calculate truckers per diem travel expense days for trips. Enter depart and return dates. Uses either whole day or 3/4 day method for partial days. 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.