MG to mL Calculator - Convert Milligrams to Milliliters and mL to mg
Free mg to mL calculator. Convert milligrams to milliliters and milliliters to milligrams using liquid concentration or density. Perfect for medication dosages, cooking measurements, and liquid conversions. Supports water, milk, cooking oil, medications, and custom concentrations. Real-time bidirectional conversion.
Last updated: January 23, 2026
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💡 Conversion Formula
mL = mg ÷ Concentration (mg/mL). Enter medication dosage to calculate liquid volume, or enter liquid volume to calculate medication dosage.
Concentration is automatically set based on selected liquid/medication
Conversion Result
Milligrams to Milliliters
100 mg = 0.1 mL
Formula: Medication Dosage ÷ Concentration = Liquid Volume
100.00 mg ÷ 1000.00 mg/mL = 0.1000 mL = 0.100000 mL
Milligrams
100 mg
Milliliters
0.1 mL
Important Notes:
- • This calculator is for educational purposes only
- • Always consult a healthcare professional for medication dosages
- • Concentration varies by substance and temperature
- • Formula: mL = mg ÷ Concentration (mg/mL)
- • For water at room temperature: 1 mg = 0.001 mL
- • For medications, always check the label for exact concentration
MG to mL Calculator Features
Liquid Types
Water, Milk, Cooking oil, Medications, Other
Select from common liquids or enter custom concentration
Medications
Acetaminophen, Ibuprofen, Amoxicillin, and more
Includes common medication concentrations for easy conversion
Directions
mg → mL and mL → mg
Enter medication dosage to calculate volume, or enter volume to calculate dosage
Units Supported
µg, mg, g | mL, L, fl oz, tbsp, tsp
Support for various weight and volume units
Speed
Instant calculations
See results immediately as you enter or change values
Flexibility
Custom density/concentration
Enter any custom concentration value for substances not in the list
Quick Example Result
Converting 100 mg of water to milliliters:
Input
100 mg
Result
0.1 mL
How Our MG to mL Calculator Works
Our mg to mL calculator converts between weight (milligrams) and volume (milliliters) using liquid concentration or density. The fundamental formula is: mL = mg ÷ Concentration (mg/mL) or mg = mL × Concentration (mg/mL). This calculator supports multiple liquid types, predefined medication concentrations, and works bidirectionally - you can calculate volume from weight or weight from volume.
How to Use the Calculator
Step 1: Select Liquid Type
Choose the liquid type: Water, Milk, Cooking oil, Medications, or Other. For medications, you'll be able to select a specific medication next.
Step 2: Select Medication (if applicable)
If you selected "Medications", choose the specific medication from the dropdown. The concentration will be automatically set. You can also select "Custom" to enter your own concentration.
Step 3: Enter Medication Dosage or Liquid Volume
Enter either the medication dosage (in mg, µg, or g) or the liquid volume (in mL, L, fl oz, tbsp, tsp, etc.). The calculator will automatically calculate the other value. You can also enter both to verify calculations.
Step 4: View Results
Results appear instantly showing the conversion, formula used, and additional unit conversions (milligrams and milliliters) for reference.
How Many mg in a mL?
The number of milligrams in a milliliter depends on the substance's density or concentration. For water at standard conditions, there are 1,000 mg in 1 mL because water has a density of 1,000 mg/mL. This relationship comes from the historical definition of the kilogram, which was originally defined as equal to one liter of water at the temperature of melting ice (0°C).
Common Liquid Densities
- • Water: 1,000 mg/mL
- • Milk: 1,035 mg/mL
- • Cooking oil: 916 mg/mL
- • Medications: Varies by formulation (typically 1-200 mg/mL)
mL to mg Conversion — mL to mg Calculator
To perform the reverse conversion (mL to mg), we rearrange the formula: mg = mL × Concentration (mg/mL). This calculator works in both directions - just enter the value you know, and the other will appear instantly!
Conversion Formulas
mL = mg ÷ Concentration (mg/mL)For converting milligrams to milliliters
mg = mL × Concentration (mg/mL)For converting milliliters to milligrams
Liquid Concentrations — How Many Milligrams in a Milliliter?
Closely related to liquid density is liquid concentration. You will often see on medication labels that the concentration is given in mg/mL. For example, a medication might be labeled as "20 mg/mL", meaning there are 20 milligrams of the active ingredient per milliliter of liquid.
Example: Medication Dosage
If a medication has a concentration of 20 mg/mL and you need 50 mg of the medication:
50 mg ÷ 20 mg/mL = 2.5 mLSo you would need 2.5 milliliters of the medication to get 50 milligrams of the active ingredient.
Understanding Density vs. Concentration
While density and concentration are related concepts, they have slightly different meanings:
Density
Refers to the mass per unit volume of a pure substance. For example, water has a density of 1,000 mg/mL at standard conditions. Density is a physical property of the substance itself.
Concentration
Refers to the amount of a solute (like medication) dissolved in a solvent (like water). For example, a medication solution might have a concentration of 20 mg/mL, meaning 20 mg of medication per mL of solution.
Both density and concentration are expressed in mg/mL and can be used interchangeably in our conversion formulas. The key is to use the correct value for your specific substance or medication.
Need other conversion tools? Check out our volume converter and weight converter.
Get Custom Calculator for Your PlatformMG to mL Calculator Examples
Input:
- Liquid: Water
- Concentration: 1,000 mg/mL
- Medication Dosage: 100 mg
Calculation:
- Formula: mL = mg ÷ Concentration
- mL = 100 mg ÷ 1,000 mg/mL
- mL = 0.1 mL
Result: 100 mg of water = 0.1 mL
This is a common conversion for water-based solutions.
Input:
- Liquid: Medications
- Medication: Morphine sulfate 20 mg/mL
- Medication Dosage: 50 mg
Calculation:
- Formula: mL = mg ÷ Concentration
- mL = 50 mg ÷ 20 mg/mL
- mL = 2.5 mL
Result: 50 mg of medication = 2.5 mL
Always consult a healthcare professional for actual medication dosages.
Input:
- Liquid: Cooking oil
- Concentration: 916 mg/mL
- Liquid Volume: 25 mL
Calculation:
- Formula: mg = mL × Concentration
- mg = 25 mL × 916 mg/mL
- mg = 22,900 mg
Result: 25 mL of cooking oil = 22,900 mg
This represents the weight of 25 milliliters of cooking oil.
5 g water
=
5 mL
100 mg milk
=
0.0966 mL
1 mL cooking oil
=
916 mg
Frequently Asked Questions
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