The Momentum is the difference between the current point (price or something else) and the point N periods ago. Momentum is calculated as a ratio of today’s price to the price several (N) periods ago.
Momentum = CLOSE(i)/CLOSE(i-N)
Where:
CLOSE(i) — is the closing price of the current bar.
CLOSE(i-N) — is the closing bar price N periods ago
To apply a Momentum Indicator