No, hubcap size is not the same as tire size. Hubcaps are often smaller than tires and come in various sizes depending on the make and model of your car. The right sized hubcap should fit snugly over the top of your tire, with no extra space around its circumference. To find out which size hubcap you need for your vehicle, measure both the outside diameter of your wheel (not including any raised lettering or designs) and also check how far down from the edge of that wheel to where it meets with a flat surface – this measurement should be between 5”-7” for most cars. Once you have these measurements, head to an automotive store or online retailer that sells hubcaps to see what would fit best on your car. Remember though – even if a set of hubcaps looks close enough in terms of sizing when compared to what came off originally, they may still not fit correctly due to differences in depth or shape so always double-check before making a purchase!