Lineweaver–Burk Plot Calculator
Fit Km and Vmax from substrate concentrations and reaction velocities via the double-reciprocal plot — slope, intercepts, R², kcat and catalytic efficiency.
How it works
1/v = (Km/Vmax)·(1/[S]) + 1/Vmax; Vmax = 1 ÷ y-intercept; Km = slope × Vmax; kcat = Vmax ÷ [E]
Taking reciprocals turns the Michaelis–Menten hyperbola into a straight line whose intercepts give Vmax and Km directly — the classic way to read enzyme kinetics off graph paper. Its weakness is that reciprocals magnify the error in the smallest velocities, which sit far to the right and steer the fit; modern practice fits the hyperbola by non-linear regression and uses this plot for display and for diagnosing inhibitor type (competitive lines meet on the y-axis, non-competitive on the x-axis).
Worked example
Six points from 0.5 to 16 mM: slope 0.0505, intercept 0.0192 → Vmax 52 (µM/min), Km 2.6 mM; with 0.01 µM enzyme kcat = 5,200 min⁻¹.
Frequently asked questions
Why does my Km come out negative?
A negative slope or intercept means the velocities do not saturate — extend to higher [S] or check for substrate inhibition.
Eadie–Hofstee or Lineweaver–Burk?
Eadie–Hofstee spreads the error more evenly; Lineweaver–Burk remains the standard teaching plot.
Related calculators
For teaching and planning — verify against your lab protocol and instrument documentation.