Similar to how much a website costs to build, knowing how long it will take to build a website also depends on the details of the project. Every project is a bit different, and the small differences in those projects can change how long it takes to finish them. The size of the website is a big factor in how long it will take to finish. Websites with many pages can take longer to build depending on how the methods used to build it. Likewise, technically sophisticated websites can also take longer to build.
One way of shortening the build time and possibly lowering the cost of the product is to use premade technologies for specific components within the website. For example, there are many e-commerce platforms already available that can integrate into website to make it an online store. The right team of web designers and developers can take multiple technologies and bring them together to build a highly functional website that fits your needs in every way.