mL to units Calculator
Convert a measured volume in millilitres (mL) into a dose in international units (U) using the medication concentration (units/mL). Common for insulin and heparin.
Quick presets (optional)
Choose a common concentration to auto-fill units/mL (e.g., U-100 insulin).
Commas accepted (e.g., 1,000).
Examples: U-100 insulin = 100 units/mL.
For insulin/heparin, units are commonly documented as whole numbers unless your protocol specifies otherwise.
Safety: Always confirm the product concentration (e.g., U-100 vs U-40 for insulin; units/mL for heparin) and follow local protocols for independent double-checks.
How mL to units Conversion Works
Some medications are dosed in units (U) rather than milligrams. A unit is a standardized measure of biological activity, so you must rely on the product’s labeled concentration in units per millilitre (units/mL).
To calculate how many units are in a measured volume, you multiply:
units = mL × (units/mL)
This is most commonly used for: insulin (often U-100 or U-40) and heparin (various units/mL strengths). Because these are high-risk medicines, always confirm the concentration and follow local independent double-check requirements.
Quick sanity check: If you increase the volume, the units should increase. If you increase the concentration, the units should increase.
Formula
Volume (mL): what you’ve drawn up / are administering
Concentration (units/mL): what the label states (e.g., U-100 insulin = 100 units/mL)
Worked Examples
Example 1: U-100 insulin. You administer 0.25 mL. How many units is that?
Step 1: Concentration = 100 units/mL
Step 2: Units = 0.25 × 100 = 25 units
Example 2: Heparin 5,000 units/mL. You draw 0.6 mL. How many units?
Step 1: Concentration = 5,000 units/mL
Step 2: Units = 0.6 × 5,000 = 3,000 units
Example 3: U-40 insulin. You administer 1.0 mL. How many units?
Step 1: Concentration = 40 units/mL
Step 2: Units = 1.0 × 40 = 40 units
When This Calculator Is Used
- •Converting insulin volumes (mL) into unit doses (U)
- •Calculating heparin doses when concentration is labeled in units/mL
- •Double-checking medication prep and documentation (units + mL)
- •Education: teaching concentration logic and “sanity checks”
Clinical safety note: Units-based medicines are high-risk. Always verify the exact concentration on the vial/pen (e.g., U-100 vs U-40 for insulin; units/mL for heparin) and follow local policies for independent checking before administration.
Related Calculators
Frequently Asked Questions
Clinical reminder: Always follow local protocols and consult medication information sheets. These examples are for calculation practice only.
References & Sources
These references support concentration-based dose calculations, unit concepts, and medication safety principles used in insulin/heparin handling.
International
Australia
Measurement & Units
Clinical Disclaimer: Always verify product labeling and local protocols before preparing or administering medications. This calculator is for educational checking only.