# IV Dose to mL & Dose to mL/hr Calculator

## 1 × Dose or Rate Formula

$\frac{O×V}{A}$
• O = Dose ordered
• V = Volume of dose available
• A = Dose available
💡 Look for a medication's concentration (e.g., 5 mg/mL). These are the values needed when calculating a dose. It doesn't matter what type of units are used in this formula.  You can figure out how many grams to give or how many milligrams to give, micrograms, units, grains, etc.  Remember to be consistent in basic mode (e.g., don't mix milligrams with grams).

## Examples

1. Dr. Smith has ordered a heparin infusion of 1,000 units/hour (u/hr) for John Doe in bed 7.  The infusion is to be mixed as 25,000 units (u) in 500 milliliters (mL) .9% NS.  What rate will the IV pump be set to?  In this example,

• Dose ordered = 1,000 u
• Volume of dose available = 500 mL
• Dose available = 25,000 u
$\frac{\mathrm{1,000 u}×\mathrm{500 mL}}{\mathrm{25,000 u}}$

The answer is an infusion at = 20 mL/hr.

2. Give 40 milligrams (mg) of Lasix® (furosemide) IVP. The vial of Lasix® contains 100 mg per 10 mL. In the example,

• Dose ordered = 40 mg
• Volume of dose available = 10 mL
• Dose available = 100 mg
$\frac{\mathrm{40 mg}×\mathrm{10 mL}}{\mathrm{100 mg}}$

The answer is a 1 × dose of = 4 mL.

## References

• Munday, L. D., & Curren, A. M. (1990). Math for meds: Dosages and solutions. (6th ed.). San Diego, CA: Wallcur Inc.
• Gage, C. B., & Toney-Butler, T. J. (2017). Dose Calculation.