diff --git a/code/game/machinery/adv_med.dm b/code/game/machinery/adv_med.dm
index ed3ea420b3..f980cfd0b1 100644
--- a/code/game/machinery/adv_med.dm
+++ b/code/game/machinery/adv_med.dm
@@ -460,7 +460,8 @@
 
 			if(occupant.vessel)
 				var/blood_volume = round(occupant.vessel.get_reagent_amount("blood"))
-				var/blood_percent =  blood_volume / 560
+				var/blood_max = occupant.species.blood_volume
+				var/blood_percent =  blood_volume / blood_max
 				blood_percent *= 100
 
 				extra_font = "<font color=[blood_volume > 448 ? "blue" : "red"]>"