Base rental = Daily rental rate × Rental days
Insurance = Insurance per day × Rental days
Parking = Parking per day × Rental days
Total rental cost = Base rental + Taxes & fees + Insurance + Fuel + Parking + Tolls + Other costs
Effective cost per day = Total rental cost ÷ Rental days
Extra-cost share = Extra costs ÷ Total rental cost × 100
Taxes & mandatory fees, fuel, tolls, and other costs are entered as whole-rental amounts. Insurance and parking are daily amounts. The calculator does not infer local taxes or rental-company fees automatically.