There are two unique aspects of Kentucky’s tax system. Both the sales and property taxes are below the national averages, while the state income tax is right around the U.S. Kentucky has a flat income tax rate of 5%, a statewide sales tax of 6% and property taxes that average $1,382 annually. Gas tax: 24.6 cents per gallon of regular gasoline, 21.6 cents per gallon of diesel.Property tax: 0.80% average effective rate.