How long does a penetration test take?
It takes as long as it takes.
Consider this – how long does it take to build a house? It depends right? And usually those that estimate get it wrong. The reason why is an infinite number of variables that influence your particular circumstances. What kind of house for a start? How big? What’s it made of? How many rooms? What types of rooms? What foundations? What ground is it built on? What planning permission is there? What is the availability of builders, plumbers, architects? Where is it? What access is there? I could bore you as we go on and on and on but you get the idea.
The same applies to a pen test. You have to decide why you want a pen test, find the right penetration testing company for you, work to their availability and resources, decide what kind of a pen test you want, what it will test, how it will test it, from where it will be tested, using what tools will it be tested, using how many resources.
If you want a rough finger in the air, work on around ten days/two weeks. But don’t hold me to it.