The 70% flipping rule is a guideline that helps real estate investors decide how much they should pay for a property they plan to fix and sell for a profit. According to this rule, investors should aim to buy a property for no more than 70% of its expected selling price after repairs. This 70% includes the purchase price and the costs of renovations. Following this rule allows investors to ensure they have enough room to cover expenses and make a profit when they sell the property.