Production, management and marketing practices vary from one cow-calf producer to the next. However, many cow-calf producers face similar decisions that occur on a frequent basis. One such decision is when to sell and replace a beef cow. The objective of this work is to determine the most profitable age of replacement females to purchase and later sell considering pregnancy status and gestation (months bred). The intent of this publication is to provide information that will assist cow-calf producers in making investment decisions for their cow herd and positively contribute to long-term profitability. We hope this publication demonstrates the impact selecting replacement females and reproductive management can have on profits.