The red region represents the cumulative interest paid after refinancing your home mortgage. The blue area represents the cumulative remaining interest to be paid under your existing mortage. The purple region is where the two regions overlap. Hence, red regions represent the periods where the interest (including the cost of refinance, e.g., appraisal fees, insurance premiums, points) is greater after refinance. The break-even points are where red and blue borders cross. In the current scenario, the break-even points are months 39 and 241.