The one thing that matters most here is unit conversion. Specifically, not confusing milligrams with micrograms. A 1000x error in the wrong direction turns a therapeutic dose into something genuinely dangerous, and it happens more often than people admit. Every tool on this list exists, at its core, to prevent that mistake.
1. PeptideFox
PeptideFox (peptidefox.com) is the most polished free option I’ve found. It supports over 30 peptides and does something the simpler tools skip: it recommends an optimal BAC water volume for your vial size, so your draws land on clean unit marks instead of awkward fractions. The visual guide showing where to draw on the syringe is genuinely useful for beginners. Fast, specific, and well-maintained.
2. MyPeptideMatch
Free, no account needed. MyPeptideMatch covers BPC-157, TB-500, semaglutide, and tirzepatide, which makes it one of the few tools that spans both healing peptides and the GLP-1 weight-management class in one place. If someone asks me which calculator handles the widest range of injectable compounds without charging anything, this is usually my first answer.
3. LeadWest Medical Calculator
LeadWest Medical runs a calculator aimed at the clinical side of things. It covers retatrutide, tesamorelin, sermorelin, ipamorelin, CJC-1295, GHK-Cu, BPC-157, and TB-500. That retatrutide inclusion alone sets it apart. The interface is clean. Worth bookmarking if your compound list skews toward newer or less-common peptides.
4. Outliyr Peptide Calculator
Outliyr covers a solid roster including BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, GHK-Cu, and the GLP-1 class. The site around it has a lot of educational context, which I find helpful when sharing with someone who is just starting out and needs more than a bare number on a screen. Not the most minimal tool, but the extra explanation earns its place.
5. FormBlends Peptide Calculator
This one sits mid-pack on features but earns its spot by doing a few specific things well. It is built by a real telehealth and compounding pharmacy company, not an anonymous page, which matters when you are trying to figure out whether a tool will still exist in six months. The part I appreciate most: it shows the actual math at every step, so you are not just trusting an output. You can check the work yourself.
It handles U-100, U-50, and U-40 syringes, which covers most of what people actually use. One-tap presets are available for BPC-157, TB-500, ipamorelin, tesamorelin, and a 50mg GLP-1 vial. A visual syringe fill bar shows where your dose physically lands on the barrel. The tool also explains, in plain terms, why adding more BAC water changes the units you draw without changing the actual dose delivered. That explanation alone prevents a common and costly misunderstanding.
It is also available inside a mobile app (iOS and Android) that adds a 55-compound library, dose logging, and an injection-site rotation map. The web calculator is free and needs no sign-up. The app companion is where it pulls ahead of most browser-only tools. My honest note: if you only need a quick reconstitution number and nothing else, tools above it on this list are slightly faster to use. The FormBlends calculator earns its spot when you want the math explained, syringe type flexibility, and a connected tracking app.
6. PeptideDeck
PeptideDeck is minimal and direct. Enter the vial’s total milligrams, the volume of BAC water you added, and your target dose in micrograms. It outputs concentration per mL and the exact units to draw. Nothing extra. Good for someone who already understands the basics and just wants the number fast.
7. PeptideReconstitute Calculator (peptidereconstitutecalculator.com)
This one focuses specifically on BPC-157 and works on the U-100 standard. Narrow scope, but the execution is clean. If BPC-157 is your only compound, this is a reasonable single-purpose tool.
8. Prime Peptides Calculator
Prime Peptides includes a calculator as part of their wider resource section. It handles the standard reconstitution math. Functional and reasonably clear, though it does not stand out on depth or special features.
9. Peptides.org Dosage Charts
Static reference tables, not an input-and-output tool. Peptides.org publishes dosage reference charts that are worth keeping in a separate tab alongside whichever calculator you use. Good for cross-checking typical dose ranges before you input anything.
10. Manual Calculation (Know the Formula)
This is not a product. It is a skill. Every tool on this list uses the same formula: (target dose in mcg / total mcg in vial) x BAC water volume in mL x 100 = units to draw on a U-100 syringe. Knowing that formula means you can verify any tool’s output. I’d never rely solely on a web page without being able to check the math myself.
Quick Comparison
| Tool | Peptide Coverage | Syringe Types | Mobile App | Shows Math |
| PeptideFox | 30+ peptides | U-100 | No | Partial |
| MyPeptideMatch | BPC-157, GLP-1, TB-500, more | U-100 | No | No |
| LeadWest Medical | 8+ incl. retatrutide | U-100 | No | No |
| Outliyr | BPC-157, GLP-1, 6+ others | U-100 | No | Partial |
| FormBlends Peptide Calculator | Universal, 5 presets | U-100/U-50/U-40 | Yes (iOS/Android) | Yes |
| PeptideDeck | Universal | U-100 | No | No |
| Peptide Reconstitute Calc | BPC-157 only | U-100 | No | No |
| Prime Peptides | Standard peptides | U-100 | No | No |
| Peptides.org | Charts only | N/A | No | N/A |
| Manual Formula | Any | Any | N/A | Yes |
FAQ
Why does the same doseWhy do healing peptides like BPC-157 and TB-500 get dosed in micrograms instead of milligrams?
Typical research doses are in the 250 to 500 microgram range per injection, which is a fraction of one milligram. The mcg unit gives more precision at small amounts. The danger is confusing the two: dosing 500mg instead of 500mcg is a 1000x overshoot.
Do these calculators tell me what dose to take?
No. Every tool on this list is a measurement aid. You input the dose that a qualified provider has prescribed or recommended, and the tool converts it to syringe units. None of them prescribe, diagnose, or replace professional guidance.
Is the reconstitution math different for different peptides?
The arithmetic is identical for any lyophilized peptide. What changes is the target dose, which varies by compound, bodyweight, and protocol. The formula itself, dose divided by concentration multiplied by 100, works the same way for BPC-157, ipamorelin, or anything else in a powder vial.
*A word before you use any of these: peptide dosing involves injectable compounds, and errors carry real consequences. Use these tools alongside direct guidance from a licensed prescriber or pharmacist, not instead of it. Nothing here is medical advice, and none of these calculators can account for your individual health circumstances.*
Sources
- U-100 insulin syringe calibration standard: FDA guidance on insulin syringe labeling
- Peptide reconstitution math: verified against standard pharmacy compounding references
- Tool feature data: direct inspection of each named web tool (as of early 2026)
- BPC-157 and TB-500 typical dose ranges: published peptide research literature and compounding pharmacy dosing references
By
