Dilution for Injection Calculator
Enter your drug amount and target concentration to instantly find how much diluent to add.
Use the Dilution for Injection Calculator
Drug & Concentration Inputs
Fill in the fields below. Units must be consistent (e.g. mg and mg/mL).
Fill in the inputs and click Calculate to see results.
Preparation Results
Step-by-Step
Dry powder: If the drug has a displacement volume, subtract it from the diluent volume shown above. Check the package insert for the manufacturer-specified displacement volume.
Summary
This calculator helps clinicians, nurses, and pharmacists determine how much diluent (saline, water, etc.) to add when preparing an injectable medication. Enter the drug amount to prepare, the stock vial concentration, and the target concentration you need. The tool instantly outputs the diluent volume required and verifies the math.
How it works
- Enter the drug amount to prepare (prescribed dose or total vial amount, e.g., 500 mg).
- Enter the stock concentration if already dissolved in liquid form.
- Enter the target concentration you need in the final syringe or bag.
- The calculator computes the drug volume to draw up and the diluent volume to add.
- Review the final volume and verify the resulting concentration before preparing.
Use cases
- Preparing IV antibiotics at a specific mg/mL concentration.
- Diluting a concentrated vial to a safe infusion rate.
- Reconstituting powder-form drugs to a target concentration.
- Checking nurse or pharmacy prep calculations before administration.
- Teaching pharmacy or nursing students medication math.
- Calculating diluent for small-volume pediatric doses.