Market Facilitation Index (MFI): The Only Indicator That Reveals Price Efficiency and Real Market Strength The MFI is calculated by taking the ratio of the range between the high and low of a candle divided by the volume, as shown in the following formula. https://recentstatus.com/post/6056_market-facilitation-index-mfi-the-only-indicator-that-reveals-price-efficiency-a.html