A valuation formula is used to determine what is the company worth. Here are 10 best calculations to help your business valuation.The Interactive Business Valuation Calculator can provide you with a rough idea of the value of your business. Liquidation value: Liabilities are subtracted from the amount that the company's assets could sell for in a liquidation sale minus liquidation expenses. Rules of thumb for business valuation provide a quick method of estimating the value of small to medium size businesses. Enter your total taxable and nontaxable sales for the reporting period, including lease and rental receipts. Business debts such as a bank loan or commercial mortgage put out to buy capital equipment are considered liabilities. The purchase agreement outlines all of the details of the sale and mirrors the LOI. I am thinking of buying a small business. Is there any easy way of calculating the estimated worth?