A lot of websites say that if you take the slope of a voltage vs time graph, you get the current. However, the math tells a different story. where V = voltage, J = joules, C = coulombs, A = amperes, s = seconds A = C / s C = A * s V = J / C J = C / V if we take the slope of Voltage vs Time, our unit is: V/s = J/(C * s) = J / (A * s^2) = (C * V) / (A * s^2) = (C * V) / (C /s * s^2) = V/s No matter what I do, I can never get the unit ampere. How is it mathematically possible that the slope of a voltage vs time graph has the unit of the current? I don't get it.