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This assumes, of course, that the cratering rate has been fairly constant for the last few billion years.
The heavy bombardment of about 3.8 billion years ago must be taken into account when using the crater age dating technique.
The size of the craters having central peaks depends on the gravity of the planet or moon: on the Moon craters larger than about 60 kilometers in diameter have central peaks while the crater diameter on the Earth needs to be larger than just 1 to 3 kilometers.
Impact cratering was especially prevalent for the first several hundred million years after the planets formed as the planets swept up left-over material.
Earth has over 170 impact craters on its continents with the 1.2-km diameter Meteor Crater in northern Arizona being one great, well-preserved example.
If you download the full-resolution version of this picture from the link on the picture, you will be able to see the rover, Opportunity next to the top left crater rim.
Most of the impact basins---craters measured in hundreds of kilometers---were made during this time.
It is noteworthy that about the time the heavy bombardment ended, life took hold.
At such speeds, the projecticle explodes on impact and carves out a round bowl-shaped depression on the surface. How can you distinguish an impact crater from a volcanic crater?
Volcano craters are above the surrounding area on mountaintops while the craters from impacts are below the surrounding area with raised rims.