Not medical advice. Talk to your provider before using any peptide.
Full disclaimerPeptide Schedule Research TeamReviewed Oct 2, 20263 Citations
Vial, BAC water and dose in. Syringe units out. You also get concentration and doses per vial, with presets for 84 injectable peptides.
The answer updates as you type
All three take the same units for the same dose. A smaller barrel just spreads it over more space.
on a U-100 syringe for a 250mcg dose
Add 2 mL BAC water to your 5 mg vial. Draw to 10.0 units on a U-100 syringe for a 250mcg dose. This vial will last 20 doses.
A peptide calculator is a free tool that converts three inputs (vial size in mg, BAC water volume in mL, and desired dose in mcg) into the exact number of syringe units to draw. Peptides are short chains of amino acids, and most ship as lyophilized powder that needs reconstitution before use. Instead of dividing concentrations on paper, you type three numbers and get a precise answer in seconds.
Call it a peptide calc or a peptide dosage calculator: it turns your vial and your dose into one line on the syringe, which takes the guesswork out of dosing.
This peptide calculator has presets for 84 injectable peptides with pre-loaded vial sizes and dosing tiers. It works as a peptide mixing calculator (concentration from any BAC water volume) and a peptide syringe calculator (units for 1mL, 0.5mL and 0.3mL U-100 syringes).
The calculator shows four numbers. Concentration is how strong your mixed vial is in mcg per mL. Draw volume is the amount of liquid for one dose. Syringe units is the line to draw to on your syringe. That's the number you actually use. Doses per vial tells you how many injections you'll get before the vial runs out.
Here's the short version: three numbers from your vial, one from your protocol. The calculator handles the rest.
New to peptides? Peptide Beginner's Guide · How to Reconstitute Peptides
More BAC water makes the solution weaker. You'll draw more units for the same dose. Less BAC water makes it stronger. Fewer units to draw, but harder to measure small doses. Standard reconstitution practice uses 0.9% benzyl alcohol in sterile water (USP <797> compounding guidelines).
Use this as a peptide BAC water calculator: change the water volume in the calculator and watch how concentration and syringe units shift. The 13setups below are common vial and water pairings. Tap a row to open that peptide's calculator with the vial, water, and dose already filled in.
Units are for a U-100 syringe. The doses are worked examples, not recommendations. Each peptide's calculator shows its sourced dose tiers.
Bottom line: if your draw is under 3 units, add more BAC water. It spreads the same dose over a bigger volume, which is easier to measure. If your draw maxes out the syringe, use less water. The mixing steps are further down this page, and the guide on how much BAC water to add has a full vial-by-water chart.
It depends on two things: peptide in the vial and dose per injection. Nothing else. BAC water changes the concentration but not the total peptide.
The math is simple: divide total peptide (in mcg) by dose per injection (in mcg). A 5mg vial = 5,000mcg. At 250mcg per dose, that's 20 doses. At 500mcg per dose, that's 10 doses. The calculator works this out for you.
Doses are one limit. Once mixed, the vial also has a usable window, so see how long a vial lasts before you plan around the dose count.
Three steps. The calculator runs all of them the moment you type.
Worked example: BPC-157.A 5mg vial with 2mL BAC water = 2,500 mcg/mL concentration. For a 250mcg dose: 250 ÷ 2,500 = 0.10 mL. On a U-100 syringe: 0.10 × 100 = 10 units. The peptide calculator mg-to-mcg conversion and all three steps happen automatically when you enter your numbers.
One mg = 1,000 mcg. That part's easy. Syringe units are different. They measure volume, not weight. A standard U-100 insulin syringe has 100 units per 1 mL, per USP insulin syringe calibration standards. How many units you draw depends on concentration, which is set by how much BAC water you added. Barrel sizes and the U-40 trap are covered in insulin syringe units explained.
IU (International Units) are used for HGH (human growth hormone) and HCG (human chorionic gonadotropin). They measure biological activity, not weight. The conversion varies by substance. Don't convert between mcg and IU unless you know your peptide's conversion factor. The Peptide Schedule syringe calculator handles 1mL, 0.5mL and 0.3mL U-100 syringes automatically.
Need to convert? Unit Converter · Reverse Calculator (convert syringe units back to mcg) · All Peptide Tools
Most peptides ship as lyophilized (freeze-dried) powder. Before injection, you add bacteriostatic water to dissolve it. The water you add sets the concentration, and the concentration sets how many units you draw. The calculator at the top of this page does that math. Six steps cover the mixing itself.
One page with the mixing math, a units-to-draw table for common vial and BAC water combinations, syringe sizes, and the safety checklist. Made to sit next to your supplies.
Want the longer walkthrough? Read the reconstitution guide.
Expert-disclosed protocols with reviewed dosing. Use a protocol to pre-fill your calculator.
Charts and worked examples for the questions the calculator raises.
Semaglutide, Tirzepatide, and Retatrutide are the most popular weight-loss peptides. They're GLP-1s. They use titration protocols: start low, step up over weeks.
Use the peptide calculator for Semaglutide, Tirzepatide, or Retatrutide by picking them from the dropdown. It auto-fills the vial size and starter dose. For full titration schedules with week-by-week dose escalation, use the dedicated calculators:
Researching which peptide fits your goal? Semaglutide vs Tirzepatide · Best Peptides for Weight Loss · Best Peptides for Muscle Growth · Best Peptides for Healing · GLP-1 Titration Protocols
Running a multi-peptide stack? Blend calculators handle two or more peptides in one vial. Enter the blend ratio, total vial size, and BAC water volume. The calculator breaks down each component's dose and syringe units separately. This also works as a peptide dilution calculator for adjusting concentration. Browse all blend calculators
Each of the 89 injectable peptides and blends has its own calculator, pre-loaded with vial sizes, BAC water defaults, and three dose tiers: beginner, moderate, and aggressive. Nothing to look up. The other 61 products get a dosing guide page instead. Or browse all 150 peptides in the directory.
