The Square Root Law , also known as the “Root Rule,” is a principle or formula used to predict how performance will change as the size of a group or team effort increases. They often apply this concept to project management , software development, and team performance analysis.
Square Root Law bases efficiency on quantity of people or effort. Other team members do not have a linear, but decreasing effect. The improvement grows with the square root of the number of members.
Mathematically, we can express it as:
Total performance = Constant value * square root(of number of people or effort)
A team with 4 members has a performance of 100 units. Adding 4 more members may not double the performance. Instead, an increase of about 2x is expected since the square root of 8 (original 4 members + added 4) is about 2.83.