<div class="container">
  <p>This is some text.</p>
</div>
<div class="container2">
  <p>This is some text.</p>
</div>
<p><a href="https://www.sitepoint.com/community/t/center-with-line-height-without-height/378946?u=sama74">https://www.sitepoint.com/community/t/center-with-line-height-without-height/378946?u=sama74</a></p>

div {
  margin-top: 20px;
}
.container {
  width: 300px;
  height: 200px;
  line-height: 200px;
  text-align: center;
  outline: 1px solid red;
}
.container2 {
  width: 300px;
  text-align: center;
  outline: 1px solid red;
  padding: 75px 0;
}