How do you go about picking the right tile? Well, you have somehow come across a blog post advising you where to start, so you're certainly doing something right. Choosing tile can be overwhelming: allow us to give you an introduction.
Tile quantities are usually fairly simple to calculate. Just grab your tape measure and calculator, and some simple math will get you there. It's always best for someone who has been in the physical space to take care of quantities. This is because they are able to understand whether their measurements are exact or approximate, lay out the room based on tile size and ideal pattern, and estimate more appropriately how much overage they'll need.