How the reconstitution calculation works
Concentration describes how much material is present in each milliliter of solution. This calculator divides the peptide amount on the vial label by the liquid volume you enter. It then converts your own target amount into a volume. It does not decide what amount is appropriate.
- Concentration in mg/mL: vial amount in mg ÷ solution volume in mL.
- Concentration in mcg/mL: concentration in mg/mL × 1,000.
- Volume in mL: target amount in mg ÷ concentration in mg/mL.
- U-100 scale units: volume in mL × 100.
- Theoretical full portions: vial amount ÷ target amount, rounded down to a whole number with matching mass units.
The calculation treats the diluent volume as the final solution volume and assumes uniform concentration. It does not account for displacement, incomplete dissolution, product purity, liquid loss, or stability. If product instructions specify a different final volume or concentration, those instructions take precedence.
mg, mcg, mL, and syringe marks measure different things
mg means milligrams and mcg means micrograms. Both measure mass: 1 mg equals 1,000 mcg. mL means milliliters and measures volume. These mass relationships follow the NIST metric prefixes.
On a U-100 scale, 100 units correspond to 1 mL. A syringe reading is not a fixed peptide mass: the mass at that volume depends on the solution's concentration. Physical graduation spacing varies between syringes. The U-100 conversion does not apply to U-40, U-500, or other scales.
Confusing mass, volume, and syringe units can cause medication errors. The FDA describes this problem in its alert about dosing errors with compounded injectable semaglutide. For medication, ask a pharmacist or prescriber to verify the concentration, syringe, and measurement.
Peptide calculator questions
Is this peptide reconstitution calculator free?
Yes. This web calculator is free and works without an account. Its inputs are processed in your browser and are not submitted by the calculator. The Dosely mobile app is a separate product with in-app subscriptions.
How do I convert mg to mcg?
Multiply milligrams by 1,000 to get micrograms. Divide micrograms by 1,000 to get milligrams. Keep the vial amount and target amount in the same mass unit before dividing.
How many U-100 units are in a milliliter?
A U-100 syringe scale has 100 units per mL, so one scale unit corresponds to 0.01 mL. This describes volume on that specific scale, not the biological activity or mass of a peptide. A physical tick on a syringe may span more or less than one unit; check its graduation spacing.
Why does the calculator ask for syringe capacity?
A calculated volume can be larger than the selected syringe holds. The calculator checks the entered values against a 0.3, 0.5, or 1 mL capacity and withholds the result if it exceeds that capacity. It does not check whether the actual graduation spacing can measure the result accurately.
Does it tell me how much diluent or peptide to use?
No. You supply every amount. The calculator provides concentration and volume arithmetic, not preparation instructions, recommended doses, compound combinations, or treatment protocols. It cannot determine whether a product is suitable or safe for use.
Can I use the calculation for a peptide blend?
The inputs describe one stated mass and one target mass. A total blend mass cannot be treated as the mass of an individual ingredient. This tool does not calculate or verify each ingredient in a blend.
Why are the results approximate?
The displayed decimals are rounded for readability. The whole-portion count uses the decimal amounts entered before rounding, but remains theoretical because real measurements and product contents can differ. Do not round a measurement to fit a syringe without professional guidance.
Keep the calculation with your records.
Dosely brings peptide schedules, logs, vial inventory, and research tools together in an app. Explore the peptide tracker or learn how reconstitution math fits together.