Loading Calculator...
Please wait a moment
Please wait a moment
This calculator assists with drug dilution calculations. Always verify calculations independently and follow institutional protocols for medication preparation.
Calculate drug concentrations and volumes for medication preparation
| Drug | Amount | Diluent Volume | Concentration |
|---|---|---|---|
| Epinephrine (1:1000 → 1:10,000) | 1 mg (1 mL) | 9 mL NS | 0.1 mg/mL |
| Morphine | 10 mg (1 mL) | 9 mL NS | 1 mg/mL |
| Fentanyl | 100 mcg (2 mL) | 8 mL NS | 10 mcg/mL |
| Midazolam | 5 mg (1 mL) | 4 mL NS | 1 mg/mL |
| Phenylephrine | 10 mg (1 mL) | 99 mL NS | 100 mcg/mL |
| Norepinephrine | 4 mg (4 mL) | 250 mL D5W | 16 mcg/mL |
Concentration = Drug Amount ÷ Total Volume
Example: 500 mg in 100 mL = 5 mg/mL
Volume = Desired Dose ÷ Concentration
Example: 50 mg dose at 5 mg/mL = 10 mL needed
% (w/v) = (g of drug ÷ 100 mL) × 100
1% = 1 g per 100 mL = 10 mg/mL
Drug dilution is the process of adding a diluent (like normal saline or D5W) to a concentrated drug solution to achieve a desired final concentration. This is essential for accurate dosing, especially for high-potency medications.
Proper dilution ensures accurate dosing, reduces medication errors, allows for precise dose adjustments, and can reduce local irritation from concentrated solutions. Many medications must be diluted before IV administration.
Common diluents include Normal Saline (0.9% NaCl), Sterile Water for Injection, D5W (5% Dextrose in Water), and Lactated Ringer's. The choice depends on drug compatibility and patient needs.
1 mg/mL = 1000 mcg/mL = 0.1% (w/v). For percentage solutions: 1% = 10 mg/mL. Ratio expressions like 1:1000 mean 1 g per 1000 mL = 1 mg/mL.
Reconstitution is adding diluent to a lyophilized (freeze-dried) powder to create a solution. Dilution is adding more diluent to an already liquid form to reduce concentration. Both require careful calculation.
Use aseptic technique, work in a clean environment (laminar flow hood when available), use single-dose vials when possible, label diluted products with date/time/concentration, and follow institutional policies for beyond-use dating.