the per diem allowance each year the dod per diem travel and transportation committee sets the per diem allowance the per diem is specific to a given travel location and can range from a standard conus rate from $ 140 per day up to $ 702 per day for out of conus rateshe per diem is specific to a given travel location and can range from a standard conus rate from $ 140 per day up to $ 702 per day for out of conus rates