An electron is approximately 1836 times lighter than a proton. The mass of an electron is approximately 9.109 × 10⁻³¹ kilograms, while the mass of a proton is approximately 1.6726 × 10⁻²⁷ kilograms. Therefore, an electron is approximately 1.6726 × 10⁻²⁷ / 9.109 × 10⁻³¹ ≈ 1836 times lighter than a proton.