Online Gerrymander calculator

Enter the by district vote counts below and hit submit to calculate the amount and direction of gerrymandering.

To see how the numbers are calculated click: view source.

For an explanation of the reasoning behind the measure, read this blog post.

Score normalization	Disenfranchised Democrats	Disenfranchised Republicans	Difference	Sum
raw
per voter

Seats / votes curve asymmetry:

Enter district votes (one line per district):

Democratic votes	Republican votes
<?php if( isset($_POST['dem_votes'])) { echo $_POST['dem_votes']; } ?>	<?php if( isset($_POST['rep_votes'])) { echo $_POST['rep_votes']; } ?>

$r) { $s++; } } $votes[] = $v; $seats[] = $s/$count; } //count asymmetric area $da = 0; $ra = 0; $c = count($votes); for( $i = 0; $i < $c; $i++) { $j = $c-$i-1; $med = ($seats[$i]+(1-$seats[$j]))/2; if( $med > $votes[$i]) { $da += $med - $votes[$i]; } else { $ra += $votes[$i] - $med; } } $da *= $inc; $ra *= $inc; //count disenfranchisement $dem_sq = 0; $rep_sq = 0; $tot = 0; for( $i = 0; $i < $count; $i++) { $excess = $dem_votes[$i] - $rep_votes[$i]; if( $excess < 0) { $rep_sq += $excess * $excess; } else { $dem_sq += $excess * $excess; } $tot += abs($excess); } if( $tot == 0) { $tot = 1; } return array( "dem" => $dem_sq/$tot , "rep" => $rep_sq/$tot, "dem_t" => $dem_sq/$target , "rep_t" => $rep_sq/$target, "target" => $target, "dem_a" => $da , "rep_a" => $ra, ); } include 'footer.php'; ?>