Precision peptide math

Hassle-free peptide calculator

Calculate reconstitution, syringe units, concentration, draw amount, and vial dose count in seconds. Supports multi-peptide blends and U-100, U-50, and U-40 syringes.

1. Syringe details

Pick the syringe you're drawing into.

2. Vial details

Add each peptide in the vial and the bacteriostatic water you'll mix in.

Total peptide in vial

5 mg

3. Desired dose

The amount per injection you'd like to draw.

Peptide library

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Prefilled calculator templates plus reconstitution math for common research peptides.

How this calculator works

Enter your vial size, bacteriostatic water volume, and desired dose — PeptideCalc Pro instantly returns exact draw units, mL, mg/mL, mcg per unit, and doses per vial for any peptide.

Reconstitution formula

  1. Concentration (mg/mL) = total peptide mg ÷ water mL
  2. Draw volume (mL) = desired dose mg ÷ concentration mg/mL
  3. Draw units = draw mL × units-per-mL of your syringe
  4. mcg per unit = (total mg × 1000) ÷ total units of water added
  5. Doses per vial = total peptide mg ÷ desired dose mg

Syringe units explained

SyringeCapacityTicks (units)Units per mLPer unit
U-100 · 1 mL1 mL1001000.01 mL
U-100 · 0.5 mL0.5 mL501000.01 mL
U-100 · 0.3 mL0.3 mL301000.01 mL
U-40 · 1 mL1 mL40400.025 mL

mL, mg, mcg & units conversion

  • 1 mL = 100 U-100 units = 40 U-40 units
  • 1 mg = 1000 mcg = 0.001 g
  • On a U-100 syringe, 1 unit = 0.01 mL
  • On a U-40 syringe, 1 unit = 0.025 mL

Common calculation mistakes

  • Confusing U-100 and U-40 syringes — units are not interchangeable.
  • Mixing mg and mcg without converting (1 mg = 1000 mcg).
  • Assuming 1 unit = 1 mL — 1 unit on a U-100 syringe is 0.01 mL.
  • Forgetting that adding more bacteriostatic water lowers concentration and increases draw volume.
  • Rounding aggressively — always keep at least one decimal for draw units.

Frequently asked questions

How do I calculate reconstitution?+

Divide the total peptide mass in the vial by the volume of bacteriostatic water you added. That gives concentration in mg/mL. Divide your desired dose (in mg) by that concentration to get the volume to draw in mL, then multiply by the syringe's units-per-mL.

What is a U-100 insulin syringe?+

A U-100 syringe has 100 tick marks on a 1 mL barrel — so 100 units = 1 mL, and each unit = 0.01 mL. U-100 0.5 mL and 0.3 mL barrels have 50 and 30 ticks respectively, but the units-per-mL is the same.

How many mcg are in one syringe unit?+

It depends on the vial. Multiply the total peptide in mg by 1000 to get mcg, then divide by the total units of water added (mL × units-per-mL). PeptideCalc Pro shows this as mcg/unit automatically.

Is this calculator medical advice?+

No. PeptideCalc Pro is a math tool for educational and research use only. It does not recommend doses or endorse human use. Always consult a licensed medical professional.