On average, it takes about two weeks to get an average size kitchen installed and fitted. There are many variables that can affect the installation time, such as the complexity of the design and layout, the quality of the materials used, and the availability of tradespeople. It's important to factor in plenty of time for ordering materials and scheduling appointments with installers. It's also a good idea to leave some extra time in case of any unexpected delays. Ultimately, it's best to speak with a qualified kitchen installer to get an accurate estimate for your specific project.