This document describes the method of determining the moisture content of a test sample of solid biofuels by drying in an oven and can be used when high precision of the determination of moisture content is necessary. The method described in this document is applicable to all solid biofuels. The moisture content of solid biofuels (as received) is always reported based on the total mass of the test sample (wet basis). NOTE Biomass materials can contain small amounts of volatile organic compounds (VOC) which can evaporate when determining moisture content by oven drying (see References [1] and [2]). The release of such compounds is quite small relative to the overall moisture content as determined by this method and is disregarded in this document.