mg to cc Conversion Calculator
Milligrams (mg) measure mass, while cubic centimetres (cc) measure volume. To move between them you need the density of the substance. Choose a preset substance, including common medications and household liquids, enter the density directly, then type either the mass or the volume and the other value appears instantly. Switch the solve direction any time to run the calculation in reverse.
Why you need density to convert mg to cc
Milligrams (mg) measure how much matter something contains (its mass), while cubic centimetres (cc) measure how much space it occupies (its volume). These are fundamentally different physical quantities, so you cannot swap one for the other without knowing how tightly packed the material is. That relationship is density: mass per unit volume. The formula is straightforward - divide the mass in milligrams by the density in mg/cc to get the volume in cc. For the reverse, multiply the volume in cc by the density to get the mass in mg. Water has a density of exactly 1 g/mL, which means 1000 mg of water occupies 1 cc. Most substances deviate from this, which is why the substance selector matters.
cc vs mL: are they the same?
Yes, one cubic centimetre (cc) equals exactly one millilitre (mL). Both measure the same volume, just named by different conventions. In medicine and pharmacy, mL is the standard, while cc is common in engineering and older medical literature. This calculator shows both labels so you can use whichever appears on your equipment or prescription. The numerical value is always identical.
Medication dose calculations
When a liquid medication label states a concentration such as 500 mg/5 mL, the density in mg/mL is simply 500 / 5 = 100 mg/mL. To find how many mL (cc) to draw up for a 250 mg dose, divide: 250 / 100 = 2.5 mL. This calculator automates that step for common medications included in the preset list. For substances not listed, select "Custom / other" and enter the concentration from the label as the density in mg/cc. Always cross-check dose calculations with the prescriber or pharmacist and read the label before administering any medication.
When water is the substance
Because water has a density of 1000 mg/cc at room temperature, the conversion is especially tidy: 1 mg of water = 0.001 cc, and 1 cc of water = 1000 mg = 1 g. This is why many dilute aqueous solutions (such as saline or most water-based medicines) approximate the water density closely enough for practical purposes, though the dissolved solutes do shift the density slightly. For high-precision work always measure or look up the actual solution density.
Common substance densities
| Substance | Density (g/mL) | Density (mg/cc) | 1 cc = (mg) |
|---|---|---|---|
| Water | 1.000 | 1000 | 1000 |
| Milk | 1.030 | 1030 | 1030 |
| Ethyl alcohol | 0.789 | 789 | 789 |
| Olive oil | 0.911 | 911 | 911 |
| Gasoline | 0.740 | 740 | 740 |
| Acetone | 0.791 | 791 | 791 |
| Glycerin | 1.261 | 1261 | 1261 |
| Propylene glycol | 1.036 | 1036 | 1036 |
| Honey | 1.420 | 1420 | 1420 |
Densities at room temperature (~20 C). Use these to convert mg to cc for any of these substances.
Frequently asked questions
How many cc is 1 mg?
It depends on the substance. For water (density 1000 mg/cc), 1 mg equals 0.001 cc. For a medication with a concentration of 10 mg/mL, 1 mg equals 0.1 cc. Divide the mass in milligrams by the density in mg/cc (or the concentration in mg/mL) to get the volume in cc.
Is 1 cc the same as 1 mL?
Yes, one cubic centimetre (cc) and one millilitre (mL) are exactly the same volume. The two units are used interchangeably in medicine and pharmacy.
How do I convert mg to cc for a medication?
Find the concentration on the label (for example 100 mg/mL). Divide the prescribed dose in milligrams by the concentration: cc = mg / concentration. For a 250 mg dose from a 100 mg/mL solution, you need 250 / 100 = 2.5 cc. Select the preset from the calculator or enter the concentration as the custom density to get the result instantly.
Why cannot I just treat mg and cc as equal?
Mass and volume are different physical quantities. A milligram measures the amount of matter, a cubic centimetre measures the space it fills. Only for water (and dilute aqueous solutions) is the shortcut 1 mL = 1 g = 1000 mg approximately valid. For any other substance you need the actual density.
What is the density of water in mg/cc?
Pure water at 20 degrees Celsius has a density of about 0.998 g/mL, rounded to 1.000 g/mL for most practical calculations. In mg/cc that is 1000 mg/cc, so 1000 mg of water fills exactly 1 cc.
Can I use this calculator for cooking or baking?
Yes. Select the closest substance (for example, "Olive oil" or "Honey") or enter a custom density. Keep in mind that kitchen scales measure mass while measuring cups measure volume, so this calculator bridges the two when a recipe lists an ingredient by one unit and your equipment measures the other.