To calculate the percentage difference, use the formula:Percentage Difference = ((New Value - Old Value) / Old Value) * 100%Let's assume the old value is 50 and the new value is 80. Percentage Difference = ((80 - 50) / 50) * 100%Percentage Difference = (30 / 50) * 100%Percentage Difference = (0.6) * 100%Percentage Difference = 60%So, in this case, the percentage difference between the old value of 50 and the new value of 80 is 60%.