Below is an example plot, where the units are on the scale of 1e-5 and 1e-6, which causes matplotlib to factor this number and display it next to the axis. import numpy as np import matplotlib.pyplot as plt x = np.arange(100) * 1e-8 y = np.random.normal(1e-5, 1e-6, size=100) plt.plot(x, y, '-') plt.tick_params(labelsize='xx-small') fig = plt.gcf() fig.set_size_inches(4, 3) fig.savefig('matplotlib_tick_unit_factor.png', bbox_inches='tight') Matplotlib plot with tick unit factors 1e-5 for Y axis and 1e-6 for the X axis: I would like to control the font size of this factor, but could not find it (not in tick_params and could not figure out if it is a Locator element). I could not find the name of this element in the anatomy of a figure. Continue reading...