The Catalytic Efficiency Calculator determines the efficiency of an enzyme by calculating the ratio of its turnover number (kcatk_\text{cat}kcat​) to its Michaelis constant (KmK_mKm​). Catalytic efficiency, kcat/Kmk_\text{cat}/K_mkcat​/Km​, provides insight into how effectively an enzyme converts substrate into product per molar concentration. Users input kcatk_\text{cat}kcat​ in s⁻¹ and KmK_mKm​ in molar units, and the calculator returns the catalytic efficiency in M⁻¹·s⁻¹ along with the substitution formula. This tool is useful for students and researchers in biochemistry studying enzyme kinetics and comparing enzyme performance.