Volumes listed below assume a final volume of 250 ml. If a volume other than 250ml is requested and any of the following additives are required (bupivacaine, fentanyl  alone or in combination), use our calculator above.
Using this chart:
Example order:
Epidural: 0.125% bupivacaine with fentanyl concentration of 2 mcg/ml.

Using the table below, this would require 62.5 ml of bupivacaine and 10 ml of fentanyl for a total volume of 62.5 + 10 = 72.5ml. Remove 72.5 ml from a 250 ml bag and then add the additives listed above for a total volume of 250 ml. 
Bupivacaine 0.5% vials (preservativefree): 
Desired concentration 
Volume needed 
0.0625% 
31.25 ml 
0.075% 
37.5 ml 
0.1% 
50 ml 
0.125 % 
62.5 ml 
Bupivacaine 0.25% vials (preservativefree): 
Desired concentration 
Volume needed 
0.0625% 
62.5 ml 
0.075% 
75 ml 
0.1% 
100 ml 
0.125 % 
125 ml 
Ropivacaine 0.5% vials (preservativefree): 
Desired concentration 
Volume needed 
0.2% (preferred) 
100ml 
Ropivacaine 1.0% ampule (preservativefree): 
Desired concentration 
Volume needed 
0.2% (preferred) 
50 ml 
Fentanyl 50 mcg/ml (preservativefree): 
Desired concentration 
Volume needed 
2 mcg/ml 
10 ml 
5 mcg/ml 
25 ml 
7.5 mcg/ml 
37.5 ml 
10 mcg/ml 
50 ml 
Hydromorphone 10 mg/ml (preservativefree):
Look carefully at vial  many contain sodium metabisulfite which cannot be used. 
Desired concentration 
Volume needed 
25 mcg/ml 
0.625 ml 
50 mcg/ml 
1.25 ml 
75 mcg/ml 
1.875 ml 

