You now have an online tool to calculate profitability of your investments for your wash bay. You need to input various details like cost of equipment, construction cost, cost of consumables and the tool churns the data using time value of money to give you the finanacial ratios which are required by financial institutions for calculating project viability.IRR : Internal Rate of Return
This is a time adjusted method of appraising capital investment decisions. This method is also called as Yield on Investment, Marginal Efficiency of Capital, Marginal Productivity of Capital. Rate of Return, NPV : Net Present Value
NPV method may be described as the summation of the present values of Cash Proceeds in each year minus the summation of present values of the net cash outflows in each year.
The decision rule for a project under NPV is to accept the project if NPV is positive and reject if negative.
NBCR : Net benefit cost ratio
You can use the tool at http://www1.kkewash.com/return_on_investment_statement_for_vehicle_Wash_equipment.html