What is the approximate percentage of carbon in the Earth’s crust ?

Carbon is a versatile element that forms the basis of all living structures. Despite its importance to life, its abundance in the Earth's physical reservoirs is relatively small. According to standard geological and chemical data, the Earth's crust contains approximately 0.02% to 0.025% carbon by mass [1]. This carbon is primarily found in the form of minerals such as carbonates (like limestone), hydrogencarbonates, and fossil fuels including coal and petroleum [1]. While the ocean serves as a much larger reservoir for carbon—containing about 93% of the Earth's total carbon—the crustal concentration remains meagre compared to major elements like oxygen or silicon . In contrast, the atmosphere contains carbon in the form of carbon dioxide at a concentration of approximately 0.03% [1]. Therefore, the approximate percentage of carbon in the Earth's crust is 0.025%.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > p. 58