Calculator
Peptide reconstitution calculator, free and no account.
Enter the vial mass, BAC water and target dose, and get the exact draw on a U-40, U-50 or U-100 insulin syringe. Works for BPC-157, TB-500, retatrutide, semaglutide, tirzepatide, and any other lyophilized peptide.
Three numbers in. Exact draw out.
- 01
Enter the vial mass (mg)
The total peptide in the vial. Read it off the label: usually 5 mg or 10 mg for research peptides, or the dose ladder for GLP-1s.
Example: 10 mg vial.
- 02
Enter the BAC water volume (mL)
How much bacteriostatic water you reconstituted into the vial. Common choices are 1 mL, 2 mL, or 3 mL depending on how concentrated you want the solution.
Example: 2.0 mL BAC water.
- 03
Enter your target dose (mcg)
The dose you intend to draw, in micrograms (mcg). The calculator handles the mg ↔ mcg conversion internally.
Example: 250 mcg target dose.
- 04
Read the result
The calculator shows the exact syringe units to draw. For the worked example, that is 5.0 units on a U-100 syringe (= 0.050 mL). It also derives the concentration, volume per dose, and doses-per-vial so you can budget vials per cycle.
Result: 5.0 u · 0.050 mL · 40 doses per vial · 5,000 mcg/mL concentration.
The terms the calculator uses.
Frequently asked.
Is the calculator free?
Yes. No account, no email, no payment. The calculator runs entirely in your browser and stores nothing. Refresh the page and your inputs are gone.
What math does it do?
Concentration = vial mass × 1,000 ÷ BAC water (mcg/mL). Volume per dose = target dose ÷ concentration (mL). Syringe units = volume per dose × 100 for a U-100 syringe (× 50 for U-50, × 40 for U-40). Doses per vial = total mcg ÷ target dose. Everything is derived live as you type.
What's BAC water?
Bacteriostatic water: sterile water with 0.9% benzyl alcohol added. It's the diluent used to reconstitute lyophilized peptides because the benzyl alcohol prevents bacterial growth over multi-dose vial use. Sold by the 30 mL bottle. Plain sterile water is also used but doesn't preserve.
What's the difference between U-100, U-50, and U-40 insulin syringes?
The number is the unit scale per 1 mL. A U-100 syringe has 100 graduations per 1 mL (10 u = 0.1 mL). A U-50 has 50 graduations per 0.5 mL. A U-40 has 40 graduations per 1 mL (older / veterinary standard). The calculator supports all three; switch the syringe type and the unit reading updates.
Does Yorkstone recommend a dose?
No. The calculator does the math on the numbers you enter, and nothing more. It will not tell you what dose to take, what compound to use, or how often. Dose decisions are between you and your clinician.
Can I save my reconstitution to my protocol?
Not in the public calculator: it keeps nothing, by design. Inside the Yorkstone app, your protocol stores compounds, doses and vial concentrations, so the same math is precomputed and you only need to glance at the syringe-fill preview.
Does it work for GLP-1 medications like semaglutide or tirzepatide?
Yes. The math is the same whatever the compound: vial mass, BAC water and target dose give the exact draw. For FDA-approved GLP-1s prescribed by a clinician, follow the prescribed dosing on the label; the calculator only does the arithmetic.
What units does it accept?
Vial mass in milligrams (mg), BAC water volume in millilitres (mL), target dose in micrograms (mcg). The calculator handles all the unit conversions (1 mg = 1,000 mcg, 1 mL = 100 units on a U-100 syringe) internally.
Next
Save these results to your protocol.
Join Yorkstone and the calculator comes with you: saved presets per compound, a syringe-fill preview, and the rest of your protocol (doses, journal, bloodwork) in one record.