The liter (L) is the most widely used metric unit of volume, equal to 1,000 cubic centimeters or one cubic decimeter, serving as the standard for beverages, fuel, and household liquids worldwide. Gasoline prices, bottled water, and milk cartons all reference liters in most countries. One liter equals approximately 1.0567 US quarts or 0.2642 US gallons.

The teaspoon (tsp) is the smallest standard cooking volume unit, equal to approximately 4.929 milliliters, found in recipes worldwide for measuring small quantities of spices, extracts, and medicine. It serves as the building block for larger measurements, with three teaspoons making one tablespoon. One US teaspoon equals exactly 1/6 of a US fluid ounce.