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For tracking and calculation purposes only. Not medical advice.
Peptide Calculator: Free Reconstitution & Dosage Tool
Use PepPal’s free peptide calculator to calculate & save reconstitution, BAC water, dosage, syringe units, and concentration from your vial size, water amount, and desired dose.
Quick summary
- Convert vial size, BAC water volume, and target dose into the exact number of syringe units to draw.
- Works for any reconstituted peptide, including Tirzepatide, Semaglutide, BPC-157, and CJC-1295.
- Free with no signup required. Click Save calculation, enter your email, and PepPal sends the setup to your inbox.
- Tool type
- Reconstitution and dose calculator
- Syringe support
- 0.3 mL, 0.5 mL, 1.0 mL (U-100)
- Unit support
- mg, mcg, mL, syringe units
- Cost
- Free, no signup
Research-use only
This tool is for tracking and calculation purposes only. It is not medical advice and does not replace guidance from a qualified professional.
Peptide reconstitution calculator
Quick presets
Load a common setup, then fine-tune it.
Tap any preset
Step 1
Syringe
U-100
Choose syringe size.
Step 2
Vial quantity
How many mg of peptides in your vial?
Step 3
Dose
Dose amount per injection. 1 mg = 1000 mcg.
Step 4
BAC water
Bacteriostatic water used to reconstitute your vial.
Advanced tools
Target units
Open
Advanced tools
Target units
units
Adjusts water to match your preferred draw.
Your draw
1.0 mL
20units
0102030405060708090100
To have a dose of 1 mg, pull to 20 units.
Vial
5 mg
Water
1 mL
Volume
0.200 mL
Save this draw so you do not need to redo the math next time.
Injection supplies for reconstitution
If you are setting up your first vial, this is the short shopping checklist that pairs with the math above. Use it as a starting point and verify each supplier link before ordering.
Recommended Supply
PEPPAL applies to eligible Peptide Partners and Pivot Labs checkout links when supported by the supplier.
Why choose Peptide Partners?
Disclosure: supply links may earn PepPal a commission at no cost to you.
Before you order
Confirm a few things on the supplier and product page before checkout.
Vial size
Match the vial mg on the label to the vial mg you plan to enter into the calculator.
BAC water volume
More water means easier measurement for small doses. Less water means smaller draws.
Syringe size
Choose the smallest syringe that fits your draw so the mark is easier to read.
For the full prep checklist with brand notes, see the peptide injection supplies guide.
How to use this peptide reconstitution calculator
The calculator turns your vial amount, BAC water volume, and target dose into the exact number of syringe units to draw. Most users finish in under a minute.
Step 1 — Pick your syringe size
Choose 0.3 mL (30 units), 0.5 mL (50 units), or 1.0 mL (100 units). Most insulin syringes are U-100, which means 100 units equals 1 mL.
Step 2 — Enter your vial amount
Type in the total peptide content in milligrams (mg) as shown on the vial label. Common amounts are 5 mg, 10 mg, 15 mg, and 20 mg.
Step 3 — Enter your BAC water volume
Type in how much bacteriostatic water you add in milliliters (mL). More water makes a less concentrated solution, which can be easier to measure for very small doses.
Step 4 — Set your target dose
Enter the dose in micrograms (mcg) or milligrams (mg). One milligram equals 1,000 micrograms.
Step 5 — Read the results
The calculator shows concentration (mcg/mL), dose volume (mL), and exact syringe units to draw. New to mixing peptides? Read the step-by-step reconstitution guide before your first vial.
Worked example: 250 mcg dose from a 10 mg vial
Say you have a 10 mg peptide vial and add 2 mL of bacteriostatic water. You want a 250 mcg dose. The math goes in three short steps.
- Concentration: 10 mg ÷ 2 mL = 5 mg/mL = 5,000 mcg/mL.
- Dose volume: 250 mcg ÷ 5,000 mcg/mL = 0.05 mL.
- U-100 syringe units: 0.05 mL × 100 = 5 units.
Pull your syringe to the 5-unit mark. The calculator above handles the same math instantly for any vial, water volume, and dose combination, including non-standard values.
Want to email this draw to yourself?
Click Save calculation in the calculator, enter your email, and PepPal sends the vial, water, dose, and unit setup to your inbox so you do not need to redo the math next time.
GLP-1 math: Tirzepatide, Semaglutide, and Retatrutide
GLP-1 peptides are the most common reason people use a reconstitution calculator. The math is the same as any other reconstituted peptide. Two things make GLP-1s feel different in practice.
- Higher doses per draw. GLP-1 doses are often listed in mg, not mcg. A 2.5 mg Tirzepatide dose on a 50 mg vial reconstituted with 1 mL of water is 5,000 mcg ÷ 50,000 mcg/mL × 100 = 5 units. A 5 mg dose on the same vial is 10 units.
- Vial sizes vary by source. Compounded and research-grade vials come in many sizes — 5 mg, 10 mg, 15 mg, 24 mg, 50 mg — so vial-by-vial math matters more than a generic chart.
- Titration over weeks. Most GLP-1 protocols start low and step up. Save each step in Pep Pal so you can see exactly what you drew last week.
Working on a multi-peptide blend in one vial, such as Tirzepatide plus Cagrilintide? Use the peptide stack calculator for per-component blend math instead of the single-vial workflow on this page.
Works with every reconstituted peptide
This calculator works for any lyophilized peptide reconstituted with bacteriostatic or sterile water. The math does not care which compound is in the vial — it only needs the vial mg, the water mL, and the dose.
GLP-1 and weight management
Tirzepatide (Mounjaro / Zepbound), Semaglutide (Ozempic / Wegovy), Liraglutide (Saxenda), Retatrutide, Survodutide, CagriSema.
Recovery and healing
BPC-157, TB-500, Thymosin Beta-4, GHK-Cu, KPV.
Growth hormone and performance
CJC-1295, Ipamorelin, Tesamorelin, GHRP-6, GHRP-2, Sermorelin, MK-677, AOD-9604.
Other research peptides
Semax, Selank, PT-141, Melanotan II, DSIP, Epithalon, Thymalin.
Understanding mg, mcg, IU, and syringe units
Most peptide math errors come from mixing up units. Here is a plain-English breakdown of the four units that show up on a vial, in a protocol, and on a syringe.
Common peptide units at a glance
Unit
Milligram (mg)
What it measures
Weight of the peptide.
Quick rule
1 mg = 1,000 mcg. Often shown on the vial label.
Unit
Microgram (mcg)
What it measures
Weight of the peptide.
Quick rule
1,000 mcg = 1 mg. Often shown on dose targets.
Unit
International Unit (IU)
What it measures
Biological activity.
Quick rule
Does not convert to mg unless the peptide has a known IU-to-mg ratio.
Unit
Syringe unit
What it measures
Volume drawn into the syringe.
Quick rule
On a U-100 syringe, 100 units = 1 mL. 5 units = 0.05 mL.
Concentration (mcg/mL) is the bridge between weight and volume. Once the vial is reconstituted, concentration tells you how many syringe units equal your target dose.
COA-verified supplier reviews
Need a source after running your math? PepPal reviews and ranks suppliers based on documentation depth, third-party testing history, shipping, and discount support.
- Peptide Partners review — current stronger pick for verification depth.
- Pivot Labs review — verified alternate option with fast domestic shipping.
- Paradigm Peptides review — additional comparison point.
- Peptide Tech review — additional comparison point.
Before you order, verify your peptide's COA and compare suppliers in the supplier directory. For broader screening criteria, read the grey-market peptide supplier guide.
Frequently Asked Questions
How do I use a peptide reconstitution calculator?
Enter your peptide vial amount in mg, the volume of bacteriostatic water in mL, and your target dose in mcg or mg. The calculator computes the concentration and shows exactly how many syringe units to draw on your insulin syringe.
Does this peptide calculator work for Tirzepatide?
Yes. The math is the same for any reconstituted peptide, including Tirzepatide, Semaglutide, BPC-157, CJC-1295, and Ipamorelin. Enter your vial amount and water volume to get the correct syringe units. Always follow the dosing instructions you were given by a qualified professional.
How do you convert peptide mg to syringe units?
Divide your vial amount (in mcg) by water volume (in mL) to get concentration. Divide your dose by that concentration to get volume in mL. Multiply by 100 for U-100 syringe units. Example: a 10 mg vial with 2 mL of water is 5,000 mcg/mL. A 250 mcg dose works out to 0.05 mL, which is 5 units.
What is the difference between mg, mcg, and IU?
Milligrams (mg) and micrograms (mcg) measure weight, where 1 mg equals 1,000 mcg. International Units (IU) measure biological activity and vary by peptide. Syringe units measure volume — on a U-100 syringe, 100 units equals 1 mL.
Is this peptide calculator free?
Yes. The PepPal peptide reconstitution calculator is free with no signup. The save feature also does not require an account: click Save calculation, enter your email, and PepPal sends the setup to your inbox.
Can I save my peptide calculations?
Yes. Click Save calculation inside the calculator, enter your email address, and PepPal emails the vial, water, dose, syringe units, and notes to you for later reference.
How much bacteriostatic water should I add to a peptide vial?
It depends on the concentration you want. More water means a less concentrated solution that is easier to measure in small doses. Common volumes are 1 to 3 mL. Run a few different values through the calculator to see how each one changes the syringe units.
What peptides can I calculate with this tool?
Any lyophilized peptide reconstituted with bacteriostatic or sterile water. That includes Tirzepatide, Semaglutide, Liraglutide, Retatrutide, BPC-157, TB-500, CJC-1295, Ipamorelin, AOD-9604, Tesamorelin, GHK-Cu, and many others.
What syringe sizes does the calculator support?
The calculator supports 0.3 mL (30 units), 0.5 mL (50 units), and 1.0 mL (100 units) U-100 insulin syringes. These are the three most common sizes for peptide administration.
Is this calculator accurate for weight-loss peptides like Tirzepatide and Semaglutide?
Yes. The math is identical for all reconstituted peptides. For GLP-1 peptides like Tirzepatide and Semaglutide, enter the vial amount, water volume, and your prescribed dose. Always follow the dosing instructions you were given by a qualified professional.
Is this a peptide syringe calculator or a dose calculator?
Both. The tool takes a dose target and returns the matching syringe units, so it works as a peptide dose calculator, a peptide syringe calculator, and a peptide reconstitution calculator in one workflow.
Is this page medical advice?
No. The calculator is a tracking and math tool for research and personal organization. It does not provide medical advice. Always consult a qualified professional for any health decision.
Preferred supplier
Peptide PartnersNeed peptides? Start with a verified supplier.
PepPal's recommended source with current discount access and established testing standards.
3rd-party testedResearch-grade supplierHigh purity batches
Sources and research notes
- 1. Forbes J, Krishnamurthy K. Biochemistry, Peptide. StatPearls. NCBI Bookshelf (2023)
- 2. U.S. Pharmacopeia. USP-NF Bacteriostatic Water for Injection monograph. USP-NF (2024)
- 3. U.S. Food and Drug Administration. Tirzepatide (Mounjaro / Zepbound) prescribing information and approved labeling. FDA (2024)
- 4. U.S. Food and Drug Administration. Semaglutide (Ozempic / Wegovy) prescribing information and approved labeling. FDA (2024)
- 5. PepPal editorial. How to reconstitute peptides: step-by-step guide for first-time users. PepPal (2026)
- 6. PepPal editorial. How to read a peptide COA: a buyer's verification workflow. PepPal (2026)
- 7. PepPal editorial. Peptide stacking 101: combining compounds safely. PepPal (2026)
Related pages
Email this calculation to yourself
Use the Save calculation button in the calculator, enter your email address, and PepPal will send the vial, water, dose, and syringe-unit setup to your inbox.
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