How to Use This Calculator
Choose “Per kg” if your protocol is written in mcg/kg, or “Flat dose” if it gives one fixed amount. For per kg, enter body weight in kg or lbs and the dose per kg. For a flat dose, enter the dose in mcg. Then add how many injections a week, the vial concentration in mcg/mL and the syringe size. Click Calculate to see the dose per injection, the units and mL to draw, and your weekly and monthly totals.
Finding the Vial Concentration
This calculator needs the concentration of your mixed vial in mcg/mL. To get it, multiply the milligrams in the vial by 1,000 and divide by the millilitres of water you added. A 5 mg vial with 2 mL of water is 2,500 mcg/mL. If you have not mixed the vial yet, the Peptide Reconstitution Calculator works it out for you. To see the draw on 0.3 mL, 0.5 mL and 1 mL syringes side by side, use the Syringe Volume Calculator.
Per kg or Flat Dose?
Some research protocols scale the dose to body weight, written as mcg/kg, so a heavier subject gets a larger amount. Others give the same fixed amount to everyone. Check which one your protocol uses before you calculate, because entering a per kg figure as a flat dose, or the other way round, gives a very different result. To convert a dose from an animal study to a human equivalent, use the Allometric Dose Scaling Calculator instead.
Who Should Use This
Researchers following a protocol written in mcg/kg or as a flat dose who need the exact syringe draw and the weekly and monthly totals.
What This Calculator Does
The Peptide Dosage Calculator turns a weight-based dose or a flat dose into the amount per injection, then into units and mL on a U-100 insulin syringe using the vial concentration. It also adds up the weekly and monthly totals from how often you inject.
Formula Used
Dose per injection (mcg) = Body weight (kg) x Dose per kg (mcg/kg), or the flat doseVolume per injection (mL) = Dose per injection (mcg) / Concentration (mcg/mL)Units to draw = Volume (mL) x 100 (U-100 syringe)Weekly total (mcg) = Dose per injection x Injections per weekBody weight in lbs is divided by 2.2046 to get kg.Example Calculation
Limitations
This is a unit-conversion tool, not dosing guidance. Weight-based dosing is a straight-line estimate that ignores body composition, organ function and metabolism, and the calculator assumes a U-100 syringe with no dead space or draw loss.
Frequently Asked Questions
How do I calculate a peptide dose by body weight?
Multiply your weight in kg by the dose per kg. At 2 mcg/kg, an 80 kg subject gets 160 mcg. If your weight is in pounds, divide it by 2.2046 first to get kg.
How many units is 160 mcg?
It depends on the vial concentration. At 2,500 mcg/mL, 160 mcg is 6.4 units. At 1,000 mcg/mL, it is 16 units. At 5,000 mcg/mL, it is 3.2 units. All three are on a U-100 syringe.
How do I find my vial concentration in mcg/mL?
Multiply the vial's milligrams by 1,000 and divide by the millilitres of water. A 5 mg vial with 2 mL of water is 2,500 mcg/mL, and a 10 mg vial with 2 mL is 5,000 mcg/mL.
Can I use this for a flat dose?
Yes. Switch the dose type to "Flat dose" and enter the amount in mcg. Body weight is then ignored.
What is the difference between mcg and mg?
1 mg equals 1,000 mcg. A 5 mg vial holds 5,000 mcg, and a 250 mcg dose is 0.25 mg.
How do I convert mcg/kg to mcg?
Multiply the dose per kg by body weight in kg. For example, 1.6 mcg/kg for a 70 kg subject is 112 mcg. If body weight is in lbs, divide it by 2.2046 first to get kg.