The P/S ratio, also known as a sales multiple or revenue multiple, is a key analysis and valuation tool for investors and analysts. The ratio shows how much investors are willing to pay per dollar of sales. It can be calculated either by dividing the company’s market capitalization by its total sales over a designated period (usually twelve months) or on a per-share basis by dividing the stock price by sales per share. Like all ratios, the P/S ratio is most relevant when used to compare companies in the same sector. A low ratio may indicate the stock is undervalued, while a ratio that is significantly above the average may suggest overvaluation.