Calculator for Fermi Rounding
Rounding with the geometric mean for values with a logarithmic scale and values appearing in Fermi problems. In Fermi problems, the magnitude of a value is estimated in powers of ten, which is equivalent to a common logarithmic scale. Rounding means the middle of the two edges to which is rounded. Normal rounding uses the arithmetic mean of 0 and 10, i.e. 5. For logarithmic scales, the geometric mean has to be applied. Fermi rounding uses the geometric mean of 1 and 10, which is the square root of 10, about 3.2. Therefore, it is rounded down up to 3 and rounded up from 4.
Please enter one value or several values separated by spaces. Every number is rounded to the next power of ten.