how deep is the earth's crust at the ocean floor

The Earth’s crust beneath the ocean floor is relatively thin, averaging about 5–10 kilometers (roughly 3–6 miles) in thickness.

Basic depth range

• The oceanic crust (the crust under the ocean basins) is much thinner than continental crust, typically about 5–10 km thick.

• In contrast, continental crust can reach 25–70 km, which is why continents stand higher than ocean basins.

Variation across the seafloor

• Near mid‑ocean ridges , where new crust is forming, the crust tends to be on the thinner end of that range (around 5 km).

• In older ocean basins far from ridges, the crust can approach the thicker end (up to about 10 km), overlain by sediments that add a bit more material above the hard basaltic layers.

From seafloor surface downward

• If you start at the seafloor itself , you pass through a thin blanket of sediments before hitting solid basaltic crust a short distance below.

• From the seafloor down to the crust–mantle boundary (the Moho), the total distance is still only on the order of several kilometers compared with the Earth’s overall radius of about 6,371 km, so oceanic crust is just a very thin outer shell.

Information gathered from public forums or data available on the internet and portrayed here.