Million standard cubic feet per day is a unit of measurement for gases that is predominantly used in the United States. It is frequently abbreviated MMSCFD. MMSCFD is commonly used as a measure of natural gas, liquefied petroleum gas, compressed natural gas and other gases that are extracted, processed or transported in large quantities. ^{[clarification needed]}

A related measure is "mega standard cubic metres per day" (MSm³/d), which is equal to 10⁶ Sm³/d used in many countries outside the United States.^[1] One MMSCFD equals 1177.6 Sm³/h.

When converting to mass flowrate, the density of the gas should be used at Standard temperature and pressure.