Earthquake Richter Energy Calculator
This calculator converts Richter (or moment) magnitude to seismic energy released using the Gutenberg-Richter energy equation, as published by the U.S. Geological Survey. The relationship between magnitude and energy is logarithmic: a one-unit increase in magnitude corresponds to roughly 31.6 times more energy. This calculator shows results in joules and also provides a TNT equivalent for intuitive comparison.
Gutenberg-Richter seismic energy formula
log10(E) = 11.8 + 1.5 * M
Where E is seismic energy in ergs and M is the earthquake magnitude. To convert ergs to joules, divide by 10,000,000 (1 erg = 10-7 joules). This formula was established by Beno Gutenberg and Charles Richter and is the standard relationship used by the USGS.
Energy comparison table
| Magnitude | Energy (Joules) | Equivalent |
|---|---|---|
| 3.0 | 2.0 x 108 | Small construction blast |
| 5.0 | 2.0 x 1011 | Small nuclear weapon |
| 6.0 | 6.3 x 1012 | Strong earthquake |
| 7.0 | 2.0 x 1014 | Major earthquake |
| 8.0 | 6.3 x 1015 | Great earthquake |
| 9.0 | 2.0 x 1017 | 2011 Tohoku earthquake |
Earthquake Richter energy calculator: frequently asked questions
What is the Gutenberg-Richter energy equation?
The Gutenberg-Richter equation relates seismic magnitude to energy released: log10(E) = 11.8 + 1.5 * M, where E is energy in ergs and M is the Richter magnitude. This gives energy in ergs, which can be converted to joules by dividing by 10,000,000.
How much more energy does each magnitude step release?
Each whole number increase in magnitude releases approximately 31.6 times more energy. A magnitude 7 earthquake releases about 31.6 times more energy than a magnitude 6 earthquake.
What is the difference between magnitude and intensity?
Magnitude measures the energy released at the earthquake source and is a single fixed value. Intensity describes the shaking effects at a specific location, which varies with distance from the epicenter and local geology.
What units does this calculator use for energy?
The calculator outputs energy in joules (J) and also shows the equivalent in megatons of TNT for context. One megaton of TNT is approximately 4.184 x 10^15 joules.
Is the Richter scale still used today?
The original Richter scale is now mainly used for historical context and local magnitude (ML). Modern seismology uses the moment magnitude scale (Mw), which is more accurate for large earthquakes. The energy formula applies to both scales.
Official sources
- U.S. Geological Survey (USGS): Earthquake Magnitude, Energy, and Intensity.
- USGS Earthquake Hazards Program: The Richter Magnitude Scale.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.