What percentage of the earths volcanoes are shield volcanoes?

There are 48 shield volcanoes on Earth (active & inactive, excluding the extinct ones). Out of approximately 1,500 volcanoes in total on the planet, shield volcanoes represent about 3%.

Shield volcanoes are composed for the most part of basalt, which is fluid lava. Their name comes from their aspect as seen from the side, looking like a shield lying on the ground. This distinctive shape comes from the build-up of broad lava sheets which spread all around the magma chamber.

The most famous ones are in Hawaii, such as Kilauea and Mauna Loa, the largest volcano on Earth.