How far from a pure fifth is an equal-tempered perfect fifth?

In equal temperament, the perfect fifth is narrowed by 2 cents compared to a natural, or Pythagorean, pure fifth. This deviation is considered a nearly imperceptible amount.12

While a pure fifth is defined by a simple frequency ratio of 3:2, equal temperament achieves its flexibility by dividing the octave into 12 equal semitones of 100 cents each. Because a fifth in this system is constructed from seven of these semitones, it is slightly flat, a compromise that allows instruments to play in all keys without the significant intonational flaws found in other tuning systems.132