These calculators require the use of Javascript enabled and capable browsers. They are to determine the fuel (gasoline or light diesel) requirements of a highway trip, and to provide some calculations required by some state highway departments for light truck logs. All entries should be numeric and may be decimal if needed. Enter time values as hours; 6 minutes is 1/10 hour. Enter fuel values in gallons. The answers are returned as calculated values, based on your entries. Be sure to take into consideration highway winds, terrain, weather conditions, load, wait time and fuel for a margin of safety when calculating requirements. Be sure to check the current highway weather for departure, along the highway and at the destination before departure. Fuel weight is calculated at 6 pounds per gallon of gas and 6.84 pounds per gallon of light diesel. (The weights are accepted averages based on specific gravity and other variables, such as temperature.) No effort is made to determine usable or unusable fuel. Time and fuel ratios are assumed at highway cruise setting for the published rating. The default safety margin is zero (0); be sure to include a good margin of time.