Price elasticity of demand (PED or Ed) is a measure used in economics to show the elasticity, or responsiveness, of the quantity demanded of service or a good to a change in its price.
Price Elasticity (PED or Ed) = Change in Quantity / Change in Price
Where,
Change in Price = ((New Price - Original Price) / Original Price)
Change in Quantity = ((New Quantity - Original Quantity) / Original Quantity)