mcg to units converter for U-100 syringes

Micrograms measure amount and syringe units measure volume, so converting between them needs the concentration of the solution. Units = mcg ÷ (concentration in mcg/mL) × 100. At 2,500 mcg/mL, 500 mcg is 0.2 mL, or 20 units on a U-100 syringe.

The formula

mcg to units: mcg ÷ concentration (mcg/mL) × 100 = units
Units to mcg: units ÷ 100 × concentration (mcg/mL) = mcg
mg to mcg: mg × 1,000 = mcg
Units to mL: units ÷ 100 = mL

Worked example

Your solution is 2.5 mg/mL, which is 2,500 mcg/mL.
To convert 500 mcg: 500 ÷ 2,500 = 0.2 mL.
0.2 mL × 100 = 20 units.
Going the other way, 8 units is 0.08 mL × 2,500 = 200 mcg.

Reference table

What one unit on a U-100 syringe contains at common concentrations
Concentration	mcg per unit	10 units	25 units	50 units
1 mg/mL	10 mcg	100 mcg	250 mcg	500 mcg
2 mg/mL	20 mcg	200 mcg	500 mcg	1,000 mcg
2.5 mg/mL	25 mcg	250 mcg	625 mcg	1,250 mcg
5 mg/mL	50 mcg	500 mcg	1,250 mcg	2,500 mcg
10 mg/mL	100 mcg	1,000 mcg	2,500 mcg	5,000 mcg

Common questions

How many mcg is one unit on an insulin syringe?

One unit is 0.01 mL, so it contains the concentration in mcg/mL divided by 100. At 2,500 mcg/mL one unit holds 25 mcg.

Can I convert mcg to units without knowing the concentration?

No. Units measure volume and mcg measure amount. The concentration is what links the two.

Are syringe units the same as IU?

No. Units on a U-100 syringe are a volume: 100 units is 1 mL. International units (IU) measure biological activity and are specific to each substance.

How many mL is 10 units?

On a U-100 syringe 10 units is 0.1 mL.

Other calculators

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