diff -ur rxvt-unicode-9.22-a/src/rxvtfont.C rxvt-unicode-9.22-b/src/rxvtfont.C
--- rxvt-unicode-9.22-a/src/rxvtfont.C	2021-01-26 13:38:12.669879617 +0100
+++ rxvt-unicode-9.22-b/src/rxvtfont.C	2021-01-26 13:39:13.257880354 +0100
@@ -1239,11 +1239,22 @@
 
       FT_Face face = XftLockFace (f);
 
+/*
+ * use ascent, descent and height from XftFont *f instead of FT_Face face.
+ * this somehow reproduces the behaviour of the line height as seen on xterm.
+
       ascent  = (face->size->metrics.ascender + 63) >> 6;
       descent = (-face->size->metrics.descender + 63) >> 6;
       height  = max (ascent + descent, (face->size->metrics.height + 63) >> 6);
       width   = 0;
 
+ */
+
+      ascent  = f->ascent;
+      descent = f->descent;
+      height  = max (ascent + descent, f->height);
+      width   = 0;
+
       bool scalable = face->face_flags & FT_FACE_FLAG_SCALABLE;
 
       XftUnlockFace (f);