Generated by SassMeister.com.

SassMeister-input-HTML.html

<h1>H1</h1>
<h2>H2</h2>
<h3>H3</h3>
<h4>H4</h4>
<h5>H5</h5>
<h6>H6</h6>

SassMeister-input.scss

// ----
// Sass (v3.3.7)
// Compass (v1.0.0.alpha.18)
// ----

$heading-map: (h1, 50px, 300, 6px 2px),
  (h2, 42px, 300, 4px 2px),
  (h3, 34px, 400, 2px),
  (h4, 26px, 400, 2px),
  (h5, 20px, 600, 2px),
  (h6, 16px, 600, 1px 2px);
  
@each $h, $h-size, $h-weight, $h-pad in $heading-map {
  #{$h},
  .headings-#{$h} {
    line-height: 20px; // arbitrary number used for example
    font-size: $h-size;
    font-weight: $h-weight;
    padding: $h-pad;
  }
}

SassMeister-output.css

h1,
.headings-h1 {
  line-height: 20px;
  font-size: 50px;
  font-weight: 300;
  padding: 6px 2px;
}

h2,
.headings-h2 {
  line-height: 20px;
  font-size: 42px;
  font-weight: 300;
  padding: 4px 2px;
}

h3,
.headings-h3 {
  line-height: 20px;
  font-size: 34px;
  font-weight: 400;
  padding: 2px;
}

h4,
.headings-h4 {
  line-height: 20px;
  font-size: 26px;
  font-weight: 400;
  padding: 2px;
}

h5,
.headings-h5 {
  line-height: 20px;
  font-size: 20px;
  font-weight: 600;
  padding: 2px;
}

h6,
.headings-h6 {
  line-height: 20px;
  font-size: 16px;
  font-weight: 600;
  padding: 1px 2px;
}

SassMeister-rendered.html

<h1>H1</h1>
<h2>H2</h2>
<h3>H3</h3>
<h4>H4</h4>
<h5>H5</h5>
<h6>H6</h6>