Convert between mg, mcg, syringe units, IU, and ml. Four modes, one tool. Enter a value, get the result instantly.
Free founding-member access while spots last. We'll send your reconstitution + a link to claim your slot.
Mass to syringe units always depends on concentration, so each answer below is given at the four concentrations you get from the usual vial and water combinations. Use the converter above for any figure not listed here.
Also searched as: 500mcg to units, 500mcg to units syringe
500 mcg is 20 units on a U-100 insulin syringe at 2.5 mg/ml, which is the concentration you get from a 5 mg vial reconstituted with 2 ml of bacteriostatic water. There is no single answer without the concentration: 500 mcg is 0.5 mg, and 0.5 mg divided by the concentration gives the volume in ml, which times 100 gives the units.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml (5 mg + 5 ml) | 50 units (0.50 ml) |
| 2.5 mg/ml (5 mg + 2 ml) | 20 units (0.20 ml) |
| 5 mg/ml (5 mg + 1 ml) | 10 units (0.10 ml) |
| 10 mg/ml (10 mg + 1 ml) | 5 units (0.05 ml) |
Also searched as: 100mcg to units
100 mcg is 4 units on a U-100 insulin syringe at 2.5 mg/ml. 100 mcg is 0.1 mg, so 0.1 mg divided by 2.5 mg/ml is 0.04 ml, which is 4 units.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml (5 mg + 5 ml) | 10 units (0.10 ml) |
| 2.5 mg/ml (5 mg + 2 ml) | 4 units (0.04 ml) |
| 5 mg/ml (5 mg + 1 ml) | 2 units (0.02 ml) |
| 10 mg/ml (10 mg + 1 ml) | 1 unit (0.01 ml) |
Also searched as: 5mg to units
A 5 mg vial reconstituted with 1 ml of bacteriostatic water fills exactly 100 units, so the whole vial is one full 100-unit syringe and 1 unit is 0.05 mg (50 mcg). Add more water and the same 5 mg spreads across more units.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml (5 mg + 5 ml) | 500 units total (1 unit = 10 mcg) |
| 2.5 mg/ml (5 mg + 2 ml) | 200 units total (1 unit = 25 mcg) |
| 5 mg/ml (5 mg + 1 ml) | 100 units total (1 unit = 50 mcg) |
| 10 mg/ml (10 mg + 1 ml) | 50 units per 5 mg (1 unit = 100 mcg) |
100 mg is 100 units only when the solution is 100 mg/ml, because 100 units is 1 ml on a U-100 syringe. At any other concentration the answer changes: divide 100 mg by the concentration to get ml, then multiply by 100.
| Concentration (vial + water) | Result |
|---|---|
| 10 mg/ml | 1,000 units (10 ml) |
| 50 mg/ml | 200 units (2 ml) |
| 100 mg/ml | 100 units (1 ml) |
| 200 mg/ml | 50 units (0.5 ml) |
Also searched as: units in mg, units/mg
mg = (units divided by 100) times the concentration in mg/ml. One unit on a U-100 insulin syringe is always 0.01 ml, so at 2.5 mg/ml a single unit is 0.025 mg, which is 25 mcg.
| Concentration | What 1 unit is worth |
|---|---|
| 1 mg/ml | 0.01 mg (10 mcg) |
| 2.5 mg/ml | 0.025 mg (25 mcg) |
| 5 mg/ml | 0.05 mg (50 mcg) |
| 10 mg/ml | 0.1 mg (100 mcg) |
10 units is 0.25 mg (250 mcg) at 2.5 mg/ml. 10 units is 0.1 ml on any U-100 syringe, and 0.1 ml times the concentration gives the dose.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml | 0.1 mg (100 mcg) |
| 2.5 mg/ml | 0.25 mg (250 mcg) |
| 5 mg/ml | 0.5 mg (500 mcg) |
| 10 mg/ml | 1 mg (1,000 mcg) |
20 units is 0.5 mg (500 mcg) at 2.5 mg/ml. 20 units is 0.2 ml on any U-100 syringe, and 0.2 ml times the concentration gives the dose.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml | 0.2 mg (200 mcg) |
| 2.5 mg/ml | 0.5 mg (500 mcg) |
| 5 mg/ml | 1 mg (1,000 mcg) |
| 10 mg/ml | 2 mg (2,000 mcg) |
50 units is 1.25 mg at 2.5 mg/ml. 50 units is 0.5 ml on any U-100 syringe, which is half of a 1 ml syringe or a full 0.5 ml syringe.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml | 0.5 mg (500 mcg) |
| 2.5 mg/ml | 1.25 mg (1,250 mcg) |
| 5 mg/ml | 2.5 mg (2,500 mcg) |
| 10 mg/ml | 5 mg (5,000 mcg) |
IU does not convert to mg by a universal factor, so no single calculator covers every substance. IU measures biological activity and mg measures mass, and the ratio between them is set per substance by a reference standard. For somatropin (HGH) the standard is 1 mg = 3 IU, so mg = IU divided by 3.
For HGH (somatropin) there are 3 IU in 1 mg. For anything else the answer is different, because IU is defined per substance against its own reference preparation, not by weight.
| HGH in mg | IU |
|---|---|
| 1 mg | 3 IU |
| 2 mg | 6 IU |
| 4 mg | 12 IU |
| 5 mg | 15 IU |
| 10 mg | 30 IU |
For HGH (somatropin) 1 IU is 0.33 mg, which is 333 mcg. Divide the IU figure by 3 to get milligrams. As above, the ratio is substance-specific and does not carry over to other molecules.
| HGH in IU | mg |
|---|---|
| 1 IU | 0.33 mg (333 mcg) |
| 2 IU | 0.67 mg (667 mcg) |
| 4 IU | 1.33 mg |
| 10 IU | 3.33 mg |
| 30 IU | 10 mg |
Multiply HGH milligrams by 3 to get IU: 1 mg is 3 IU, 5 mg is 15 IU, 10 mg is 30 IU. To go the other way, divide IU by 3.
Every figure above assumes a U-100 insulin syringe, where 1 unit is 0.01 ml. Check your syringe: a U-40 syringe uses a different scale and the numbers will not transfer. These conversions are arithmetic, not dosing advice. Klarovel builds protocols from your health data and does not sell, source, or ship peptides.
The six conversions you encounter most often when working with peptides. Every one reduces to a single multiply or divide.
mg → mcg
× 1,000
0.25 mg = 250 mcg
mcg → mg
÷ 1,000
500 mcg = 0.5 mg
ml → units
× 100
0.1 ml = 10 units
units → ml
÷ 100
25 units = 0.25 ml
mg → IU
× 3
1 mg ≈ 3 IU
IU → mg
÷ 3
6 IU ≈ 2 mg
All three sizes use the same standard: 1 unit = 0.01 ml. The math never changes. Only the maximum capacity differs.
| Syringe | Capacity | Max units | Best for |
|---|---|---|---|
| 0.3 ml | 0.3 ml | 30 | Small doses under 30 units. Finest markings. |
| 0.5 ml | 0.5 ml | 50 | Moderate doses between 30-50 units. |
| 1.0 ml | 1.0 ml | 100 | Large doses or loading protocols up to 100 units. |
Peptide doses are prescribed in weight (mg or mcg), but you measure them in syringe units. The bridge between the two is concentration, expressed as mg/ml.
Concentration is set during reconstitution: divide the total peptide in the vial by the volume of water you added. A 5 mg vial with 2 ml of BAC water gives you 2.5 mg/ml.
Once you know the concentration, every conversion is the same two steps. To go from dose to units: divide the dose (mg) by the concentration (mg/ml) to get ml, then multiply by 100 for units. To reverse it, divide units by 100 to get ml, then multiply by the concentration.
Forward: units = (dose_mg ÷ concentration) × 100
Reverse: dose_mg = (units ÷ 100) × concentration
Example: 250 mcg at 2.5 mg/ml → (0.25 ÷ 2.5) × 100 = 10 units
Units, mass, volume, and how they relate.
Go beyond the calculator
The Klarovel engine maps your questionnaire and goals against a 41-peptide catalog, resolves contraindications, calibrates dosing, and sets the cycling schedule. Clinician-reviewed before delivery. Free forever for the founding 97 members.
12 minutes. Free forever. After the 97 fill, access becomes a paid subscription.
Reviewed by the Klarovel Medical Advisory Board. Last updated .
Concentration, dose conversion, half-life — the math beneath every unit conversion the calculator does for you.
Read guideReconstitution determines your vial concentration, which determines how unit conversions land. Read this first.
Read guideOnce you know the unit count, the syringe choice, angle, and rotation pattern that matters per-peptide.
Read guide