The purposes of this research study were 1) to study cost and return on investment from rice RD41 farming of the farmers in Samchuk district, Suphanburi province 2) to analyze cost and return on investment from rice RD41 farming of the farmers in this area. The sample of 10 farmers who were member of Samchuk Agricultural Cooperative having rice farms which the area between 10 to 50 rai, drawn by the method of purposive sampling because the management methods of rice farm did not different. The study was conducted by collecting data and analyzing the data obtained by in-depth interviews, the tool was interview questions. Quantitative data were analyzed using the following cost, profit, Net profit to cost ratio, Net profit to sales ratio, Return on investment and break-even point. Results of cost and return indicated that total average cost was 4,420.25 baht per rai, while average net profit was 1,209.86 per rai. Net profit to cost ratio was 26.37%, while net profit to sales ratio was 20.01%. Return on investment (ROI) was 22.54% and break-even point was 0.21 tons per rai. Cost of rice RD41 comprised 3 important costs which were 12.06% of raw material cost, 35.59% of labor cost and 52.35% of overhead cost.
Keywords: Cost, Return, Ratio, Rice RD41, Rice cultivation