Printable Log Graph Paper (Free PDF)

On log paper the lines inside each decade are not evenly spaced: the gap from 1 to 2 is far wider than the gap from 8 to 9, because each line sits at the logarithm of its value. That is the whole point — plot exponential data on it and you get a straight line. Every ruling here is placed at its true log position, and each line from 1 to 9 is labeled so you can read a value off the page without counting.

The semi-log sheet has three decades up the vertical axis and a linear horizontal grid at 1/10 inch, with a heavier line every inch. Use it for growth and decay, half-lives, pH, sound levels, bacterial counts and anything that spans several orders of magnitude on one axis only. Straight lines on it mean exponential behaviour, and the slope gives you the rate.

The log-log sheet is a 3 cycle by 4 cycle grid with square decades, so a straight line's slope reads directly as the exponent of a power law. It suits calibration curves, frequency response, particle size distributions, scaling laws and Bode-style plots. Both sheets are plain vector pages with a dark frame around the plotting area and nothing to fill in on screen.