diff --git a/code/game/machinery/adv_med.dm b/code/game/machinery/adv_med.dm
index b1cf9bac081..ed3ea420b36 100644
--- a/code/game/machinery/adv_med.dm
+++ b/code/game/machinery/adv_med.dm
@@ -287,8 +287,9 @@
 			var/bloodData[0]
 			if(H.vessel)
 				var/blood_volume = round(H.vessel.get_reagent_amount("blood"))
+				var/blood_max = H.species.blood_volume
 				bloodData["volume"] = blood_volume
-				bloodData["percent"] = round(((blood_volume / 560)*100))
+				bloodData["percent"] = round(((blood_volume / blood_max)*100))
 
 			occupantData["blood"] = bloodData