Richter scale

American  

noun

1. a scale, ranging from 1 to 10, for indicating the intensity of an earthquake.

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Richter scale British  

/ ˈrɪxtə /

noun

1. a scale for expressing the magnitude of an earthquake in terms of the logarithm of the amplitude of the ground wave; values range from 0 to over 9 Compare Mercalli scale See also magnitude

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Richter scale Scientific  

/ rĭk′tər /

1. A logarithmic scale used to rate the strength or total energy of earthquakes. The scale has no upper limit but usually ranges from 1 to 9. Because it is logarithmic, an earthquake rated as 5 is ten times as powerful as one rated as 4. An earthquake with a magnitude of 1 is detectable only by seismographs; one with a magnitude of 7 is a major earthquake. The Richter scale is named after the American seismologist Charles Francis Richter (1900–1985).

2. See Note at earthquake

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Richter scale Cultural  

1. A scale used to rate the intensity of earthquakes. The scale is open-ended, with each succeeding level representing ten times as much energy as the last. A serious earthquake might rate six to eight, and very destructive quakes rate higher.

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Discover More

No quake greater than nine has ever been recorded.

Etymology

Origin of Richter scale

1935–40; after Charles F. Richter (1900–85), U.S. seismologist

Compare meaning

How does richter-scale compare to similar and commonly confused words? Explore the most common comparisons:

• Mercalli scale vs. Richter scale

Example Sentences

Magnitudes on the Richter scale are measured logarithmically, with each whole number increase representing ten times more in measured amplitude.

From Barron's • May 11, 2026

On the rhetorical Richter scale of presidential admonishments, this was seen by the prime minister's team as pretty minor, not least because later in the same exchanges Trump described Xi as a "friend".

From BBC • Jan. 30, 2026

Earlier this year, a government panel estimated that there is an 80% chance of a magnitude 8 to 9 megaquake on the Richter scale occurring along Japan’s Nankai Trough in the next 30 years.

From Los Angeles Times • Jul. 8, 2025

Subtle tremors that had begun in June 2024 turned into full-fledged earthquakes, some exceeding 4.0 on the Richter scale, shaking homes and unsettling the island's residents.

From BBC • Feb. 7, 2025

Like Iris Chacon inside a washing machine during an earthquake, Richter scale 8.9.

From "Bodega Dreams" by Ernesto Quinonez