\(E^{d}_{p_{x}} = \frac{\%\Delta Q^{d}_{x}}{\%\Delta P_{x}}\ or\ E^{d}_{p_{x}} = (\frac{\Delta Q^{d}_{x}}{\Delta P_{x}})\times (\frac{P_{x}}{Q^{d}_{x}})\)

- \(E^{d}_{p_{x}}\) – own-price elasticity of demand
- \(Q^{d}_{x}\) – quantity demanded of good "X"
- \(P_{x}\) – price per unit of good "X"