The Richter scale is logarithmic. Each whole-number jump indicates a tenfold increase in wave magnitude and a 31.7 increase in energy released. For example, a Richter 9 earthquake has 100 times the magnitude and 1004.89 times the energy of a Richter 7 earthquake.
To calculate the increase in magnitude, subtract the two Richter numbers and raise 10 to the power of the difference. To calculate the increase in energy, raise 31.7 to the power of the difference. Most earthquakes measure less than 3 on the Richter scale and can barely be felt by humans. Another scale, the Mercalli scale, rates the amount of destruction caused by an earthquake.