SCSS

HTML

<div class="class1">Hello World</div>
<div class="class2">Hello World</div>

SCSS

$startWidth: 100px;
$endWidth: 100px;

.class1 {
  max-width: calc(100% - #{$endWidth});
  min-width: $startWidth;
  text-overflow: ellipsis;
}

.class2 {
  max-width: calc(100% - #{$startWidth});
  direction: rtl;
}