Equal width using flex and border-box

Question

I am using box-sizing: border-box; with varying border thicknesses within a flexbox. I want the elements within the flexbox to have equal widths, b

Answer 1

your problem is here flex: 1; change it to flex: 1 0 20%; even for more/less elements. no need to calculate the width using calc as others mentioned.

also just change this:

.container .block {
  height: 28px;
  flex: 1;
  border: 1px solid black;
  box-sizing:         border-box;
}

to:

.container .block {
  height: 28px;
  flex: 1 0 20%;
  border: 1px solid black;
    -moz-box-sizing:    border-box;
  -webkit-box-sizing: border-box;
    box-sizing:         border-box;
}

DEMO: https://jsfiddle.net/4aww81wv/