Index: firmware/App/Modes/Rinseback.c
===================================================================
diff -u -rebfb8019ba74b6c614051d1bfd13ee186c9138fd -r70d33c50c8c3fd987f39eaa1f3b294860d569830
--- firmware/App/Modes/Rinseback.c	(.../Rinseback.c)	(revision ebfb8019ba74b6c614051d1bfd13ee186c9138fd)
+++ firmware/App/Modes/Rinseback.c	(.../Rinseback.c)	(revision 70d33c50c8c3fd987f39eaa1f3b294860d569830)
@@ -338,17 +338,14 @@
 static RINSEBACK_STATE_T handleRinsebackRunState( void )
 {
     RINSEBACK_STATE_T result = RINSEBACK_RUN_STATE;
-    U32 bldPumpMotorCount = getBloodPumpMotorCount();
-    U32 bldPumpMotorDelta = u32DiffWithWrap( rinsebackLastMotorCount, bldPumpMotorCount );
 
     // Reset rinseback t/o
     rinsebackTimerCtr = 0;
 
     // Update rinseback volume delivered so far
     cumulativeRinsebackVolume_mL += ( getMeasuredBloodFlowRate() * RINSEBACK_FLOW_INTEGRATOR );
     // update independent calculated safety volume delivered so far
-    rinsebackMotorCount += bldPumpMotorDelta;
-    rinsebackLastMotorCount = bldPumpMotorCount;
+    rinsebackMotorCount = u32DiffWithWrap( rinsebackLastMotorCount, getBloodPumpMotorCount() ) / BP_HALL_EDGE_COUNTS_PER_REV;
     rinsebackVolumeDelivered_Safety = ( (F32)rinsebackMotorCount * VOLUME_PER_BP_MOTOR_REV_ML );  // TODO - include upstream pressure compensation to this calc
 
     // Has user requested to end rinseback?