In this video i will talk about Box Sizing in CSS. The CSS box-sizing property allows us to include the padding and border in an element's total width and height. Without the CSS box-sizing Property By default, the width and height of an element is calculated like this: width + padding + border = actual width of an element height + padding + border = actual height of an element This means: When you set the width/height of an element, the element often appears bigger than you have set (because the element's border and padding are added to the element's specified width/height). With the CSS box-sizing Property The box-sizing property allows us to include the padding and border in an element's total width and height. If you set box-sizing: border-box; on an element, padding and border are included in the width and height: