How this calculation works
The endpoints count when prime. For an interval starting at 0 or 1, the first possible listed value is 2.
THE FORMULA
Count integers with no divisors from 2 through their square rootA worked example
There are six primes between 10 and 30, from 11 through 29.
Good to know
Both endpoints are included.
Reference: NIST DLMF, Functions of Number Theory (opens in a new tab) ↗
Read the result
List primes in an inclusive interval and count them.
The primary result is labeled “Prime count”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
Both endpoints are included.
For a related exercise, try the greatest common divisor.
A few questions, answered
How can I check the default inputs by hand?
There are six primes between 10 and 30, from 11 through 29.
Which rule does this calculator apply?
Count integers with no divisors from 2 through their square root