Fisher's equation
From ACT Wiki
Economics.
A formal expression of the quantity theory of money defining the relationship between the quantity of money in the economy, its velocity of circulation, the number of transactions over a given period and the general level of prices.
The equation is conventionally expressed as: P = MV/T
Where:
P = the general level of prices
M = the quantity of money in the economy
V = its velocity of circulation, and
T = the volume of transactions in a given period.