According Briggs, in the United States the transportation fuel and home heating oil use is about 230,000 million US gallons, the equivalent of 870 km³ only during 2004. Considering this statistic, waste vegetable oil and animal fats would not be enough to meet the biodiesel demand. In fact in the USA the estimated production of vegetable oil for all uses is about 23,600 million pounds, around 12,000,000 tons or 3,000 million US gallons, the equivalent of 11,000,000 m³. Van Gerpen published that the estimated production of animal fat is 11,638 million pounds, (5,000,000 tons) during the same 2004.

Base oils can be processed to produce biodiesel, including rapeseed, soybean oils and virgin oil feedstock as the most commonly used. However, the fuel may be processed from any other crop such as, palm oil, hemp, mustard, algae and waste vegetable oil. It can also be produced from animal fats including lard, yellow grease, tallow, or as a byproduct from the production of Omega-3 fatty acids from fish oil. However, the available supply worldwide is drastically less than the amount of petroleum-based fuel that is burned for transportation and home heating.

Soybeans are most commonly used to produce biodiesel, but these oils are not a very efficient crop solely for the production of fuel. Their common use in the United States for food products has led to soybean fuel becoming the primary source for biodiesel in this nation, with soybean producers lobbying to increase awareness of soybean biodiesel, expanding at the same time the market for their product.

In Europe, rape seed is the most common base oil used in biodiesel production. In countries, like Malaysia and Indonesia pilot-scale production from palm oil has already started. In India and Southeast Asia, the Jatropha tree is used as a significant fuel source which is also planted for watershed protection, as well as for other environmental restoration efforts.

Bred mustard varieties can produce reasonably high oil yields having the added benefit that the meal leftover after the oil has been pressed out can act as a very effective, biodegradable and non-toxic pesticide. In addition, the production of algae to harvest oil for biodiesel has not been undertaken on a commercial scale. On the other hand, many advocates suggest that waste vegetable oil is the best source of oil to produce biodiesel.