mcg to mL Converter
Micrograms measure mass and milliliters measure volume, so the label’s concentration bridges them: mL = mcg ÷ mcg/mL. Pick a common strength or enter your own.
Example: with Dose (mcg) 500 · Concentration 1,000 mcg/mL (B12 injection) · Custom concentration (mcg/mL) 1000 → Volume to draw: 0.5 mL.
Computed by the calculator below using its default values. Change any input to see your own numbers.
💉 Measure doses precisely with oral syringes
Check it outmcg to mL: divide by the concentration
Liquid medications state a concentration — how many micrograms sit in each milliliter. Divide the dose by it: at the common B12 strength of 1,000 mcg/mL, a 500 mcg dose is 0.5 mL, 250 mcg is 0.25 mL, and 1,000 mcg is a full milliliter. At 500 mcg/mL the same 1,000 mcg dose doubles to 2 mL. Many people draw B12 in U-100 insulin syringes, where 100 units = 1 mL — so 0.5 mL sits at the 50-unit mark.
To go the other way (mL to mcg), multiply volume by concentration: 0.75 mL of a 200 mcg/mL solution carries 150 mcg. Always take the concentration from your specific vial — the same drug is sold in several strengths, and using the wrong one scales the dose by exactly that ratio.
How it’s calculated
Volume (mL) = dose (mcg) ÷ concentration (mcg/mL). Preset strengths cover common injectables (1,000, 500, and 100 mcg/mL); the custom field accepts any labeled value. The syringe row converts via the U-100 standard, 100 units = 1 mL, so units = mL × 100. Reverse conversion: mcg = mL × mcg/mL.
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Common mistakes
- Using a universal mcg-to-mL factor — there isn't one; every solution has its own concentration.
- Reading 1 mg/mL as 1 mcg/mL — 1 mg/mL equals 1,000 mcg/mL.
- Assuming syringe units equal mL — on a U-100 syringe, 100 units = 1 mL.
Frequently asked questions
How many mL is 500 mcg?
At 1,000 mcg/mL it’s 0.5 mL; at 500 mcg/mL, 1 mL; at 100 mcg/mL, 5 mL. The concentration on your vial decides.
What is 1000 mcg in mL?
Divide by the strength: 1,000 mcg of a 1,000 mcg/mL solution is exactly 1 mL; of a 500 mcg/mL solution, 2 mL.
How many mcg in 1 mL?
Exactly the concentration printed on the label: 1 mL of a 1,000 mcg/mL solution carries 1,000 mcg, which is 1 mg.
How do I convert mL back to mcg?
Multiply volume by concentration: 0.3 mL × 1,000 mcg/mL = 300 mcg. Keep units consistent — convert mg/mL to mcg/mL by multiplying by 1,000 first.