Etymology Map
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Ratio

2 stages from Latin to English.

Today it means the relation between two amounts

Where does the word "ratio" come from? It comes from Latin ratio, adopted directly into English (1630s).

1
Stage 1 of 2
ratio
Latin · ancient
"reckoning, reason"
from 'reri', to reckon; the same root as 'reason' and 'ration'
2
Stage 2 of 2
ratio
English · 1630s
"quantitative relation"
introduced by mathematicians for proportion
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Read the full story

Ratio’s story begins in Latin: ratio meant “reckoning, reason.” From 'reri', to reckon; the same root as 'reason' and 'ration'. It reached English by 1630s as ratio. Introduced by mathematicians for proportion. Today, ratio means the relation between two amounts.