Simple Sass @for loop to build grid classes at 5% width intervals. Generated by SassMeister.com.

_grid.scss

// ----
// Sass (v3.3.0.rc.1)
// ----

@for $i from 1 through 20 {
  .grid-#{($i * 5)} {
    width: ($i * 5%);
  }
}

grid-output.css

.grid-5 {
  width: 5%;
}

.grid-10 {
  width: 10%;
}

.grid-15 {
  width: 15%;
}

.grid-20 {
  width: 20%;
}

.grid-25 {
  width: 25%;
}

.grid-30 {
  width: 30%;
}

.grid-35 {
  width: 35%;
}

.grid-40 {
  width: 40%;
}

.grid-45 {
  width: 45%;
}

.grid-50 {
  width: 50%;
}

.grid-55 {
  width: 55%;
}

.grid-60 {
  width: 60%;
}

.grid-65 {
  width: 65%;
}

.grid-70 {
  width: 70%;
}

.grid-75 {
  width: 75%;
}

.grid-80 {
  width: 80%;
}

.grid-85 {
  width: 85%;
}

.grid-90 {
  width: 90%;
}

.grid-95 {
  width: 95%;
}

.grid-100 {
  width: 100%;
}