The magnitude of acceleration of an object in free fall near the surface of the Earth is approximately 9.8 m/s². This value is often rounded to 10 m/s² for simplicity in calculations.

This acceleration is also known as the acceleration due to gravity, and it's denoted by the letter g. It's important to remember that this value is an approximation, as the actual acceleration due to gravity varies slightly depending on factors like altitude and latitude.