Folate Requirement (DFE) Calculator

About this calculator

Dietary Folate Equivalents (DFE) let you compare naturally occurring food folate with synthetic folic acid, which the body absorbs roughly 1.7 times more efficiently on an empty stomach. The standard conversion is DFE = mcg food folate + (1.7 × mcg folic acid from fortified food or supplements taken with meals), or a factor of 2 for supplements taken without food — the U.S. RDA is 400 mcg DFE/day for most adults, rising to 600 mcg during pregnancy to help prevent neural tube defects.

Because folic acid is so much better absorbed than food folate, simply adding up milligrams from a cereal box and a spinach salad would understate your actual intake — DFE corrects for that so it can be compared directly against the RDA. Registered dietitians, prenatal care providers, and public health nutritionists use this conversion to counsel patients, especially those planning pregnancy, on whether their combined diet and supplement intake meets folate recommendations.