Lab tool
Unit converter
Mass and volume conversions for peptide handling — the decimal places most likely to cause a mistake, done for you.
The short answer
Every metric mass step is a factor of 1,000: 1 g = 1,000 mg = 1,000,000 mcg = 1,000,000,000 ng. Volume works the same way — 1 L = 1,000 mL = 1,000,000 µL — and 1 mL is the same volume as 1 cc.
Syringe units are different: one unit on a U-100 insulin syringe is 0.01 mL, so 100 units is 1 mL. A unit is a volume, not a mass, so it only becomes micrograms once you know the concentration of the solution — multiply the units by 0.01 to get millilitres, then by the concentration.
These conversions are measurement arithmetic for laboratory work. The materials referenced are supplied as laboratory research material, not as drugs, supplements or consumer products.
Mass
Volume
Syringe units, volume and mass
A unit is a volume — 0.01 mL on any U-100 barrel. Set the concentration of the solution and the two rows below convert in both directions. Not sure of the concentration? The reconstitution calculator works it out from the vial mass and the diluent volume.
Volume and mass
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Syringe units
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Quick reference: metric prefixes
| 1 g | 1,000 mg | 1,000,000 mcg | 1,000,000,000 ng |
|---|---|---|---|
| 1 mg | 0.001 g | 1,000 mcg | 1,000,000 ng |
| 1 mcg | 0.001 mg | 0.000001 g | 1,000 ng |
| 1 mL | 1,000 µL | 0.001 L | 1 cc |
Note that IU (international units) are activity-based and specific to each substance — there is no universal IU-to-mass conversion, so any IU figure must come from the material's own certificate of analysis.
Quick reference: U-100 syringe graduations
| Units | mL | µL | mcg at 5 mg/mL |
|---|---|---|---|
| 1 | 0.01 | 10 | 50 |
| 2 | 0.02 | 20 | 100 |
| 5 | 0.05 | 50 | 250 |
| 10 | 0.1 | 100 | 500 |
| 20 | 0.2 | 200 | 1,000 |
| 25 | 0.25 | 250 | 1,250 |
| 30 | 0.3 | 300 | 1,500 |
| 50 | 0.5 | 500 | 2,500 |
| 100 | 1 | 1,000 | 5,000 |
The last column assumes a 5 mg/mL solution — what a 10 mg vial reconstituted with 2 mL of diluent gives. At any other concentration, scale it: a 10 mg/mL solution carries twice as much in the same number of units.
Common questions
How many mcg are in a mg?
One milligram is 1,000 micrograms. Going the other way, one microgram is 0.001 mg. Each step down the metric prefixes — gram to milligram to microgram to nanogram — is a factor of 1,000, so 1 g = 1,000 mg = 1,000,000 mcg = 1,000,000,000 ng.
How many units is 1 mL on an insulin syringe?
On a U-100 insulin syringe, 1 mL is 100 units and one unit mark is therefore 0.01 mL, or 10 µL. That ratio is set by the U-100 scale and holds for every barrel size: a 0.3 mL barrel has 30 graduations and a 1 mL barrel has 100, but each graduation is the same 0.01 mL.
How do you convert syringe units to mg?
A unit is a volume, not a mass, so it only becomes a mass once the concentration of the solution is known. Convert the units to millilitres by multiplying by 0.01, then multiply by the concentration. 20 units of a 5 mg/mL solution is 20 × 0.01 = 0.2 mL, and 0.2 mL × 5 mg/mL = 1 mg.
Is 1 mL the same as 1 cc?
Yes. A cubic centimetre and a millilitre are the same volume, so a syringe marked 1 cc and one marked 1 mL hold the same amount. One millilitre is also 1,000 microlitres.
Can IU be converted to mg?
Not with a general formula. An international unit is a measure of biological activity defined separately for each substance, so the IU-to-mass ratio differs from one material to the next and can differ between preparations of the same material. Any IU figure has to come from the certificate of analysis for the specific lot.