How long does it take for hpv to become cancer?

Depends: No definite answer. Hpv virus can cause mutations which can lead to cancer development. Our body often clears hpv on its own before mutations that lead to cancer can develop.

Years/decades/never: Just because you acquire this germ does not mean you will develop cancer. It gives you a heads up so you may be better motivated to do regular health screenings.At the short end cervical cancer (or other forms) may arise after a few years/decades or never. Women have been doing related pap smear screenings for decades before we knew HPV could eventually cause the problem.