diff --git a/betterlockscreen b/betterlockscreen
index b171e08..cc74275 100755
--- a/betterlockscreen
+++ b/betterlockscreen
@@ -158,7 +158,10 @@ lockselect() {
 logical_px() {
 	# get dpi value from xrdb
 	local DPI
-	DPI=""$(xdpyinfo | sed -En "s/\s*resolution:\s*([0-9]*)x([0-9]*)\s.*/\\$2/p" | head -n1)
+	DPI=$(cat ~/.Xresource | grep -oP 'Xft.dpi:\s*\K\d+' | bc)
+	if [ -z "$DPI" ]; then
+		DPI=$(xdpyinfo | sed -En "s/\s*resolution:\s*([0-9]*)x([0-9]*)\s.*/\\$2/p" | head -n1)
+	fi
 
 	# return the default value if no DPI is set
 	if [ -z "$DPI" ]; then