Work out prime numbers in a range instantly with clear inputs, formula shown and shareable results.
Testing each candidate by trial division up to its square root finds all primes in a range. The prime number theorem predicts a density near 1/ln x, which the reported percentage can be compared against.
Prime density
π(x) ≈ x / ln x, so density near x is about 1 / ln x
21, summing to 3167.
Yes. There are 25 primes below 100 but only 21 between 100 and 200, and the density keeps falling like 1/ln x.