The single thing that matters most when reconstituting peptides is getting the unit conversion right. Miss it by a factor of 1,000 and you are injecting ten times your intended dose. That is not a hypothetical. Mixing up milligrams and micrograms is the most common serious mistake beginners make, and it happens because the arithmetic is easy to get wrong without a reliable reference.
This list covers ten calculators and dosing tools available in 2026. Some are full-featured apps. Some are one-page utilities with no company behind them. The goal here is to tell you what each one actually does, so you can pick the right one for where you are in the process.
What I Looked At
- Does it handle the mg-to-mcg conversion, or leave that to you?
- Does it support multiple syringe types (U-100, U-50, U-40)?
- Is the underlying math visible or hidden?
- Is there a real organization behind it, or is it an anonymous page?
- Does it work for any lyophilized peptide, or only specific compounds?
The 10 Tools
1. FormBlends Peptide Calculator
Free, no account required, and it shows you the actual arithmetic rather than just spitting out a number.
You enter three things: how much peptide is in the vial (mg or mcg), how much bacteriostatic water you added in mL, and your target dose per injection. The tool outputs the concentration per mL, the exact units to draw on your syringe, and the total number of doses in the vial. It defaults to U-100 syringes but also supports U-50 and U-40, which matters if your supply situation changes. A visual syringe fill bar shows precisely where your dose lands on the barrel. One-tap presets cover the most commonly reconstituted peptides including BPC-157 at both 5 mg and 10 mg vials, TB-500 at 5 mg, ipamorelin at 10 mg, tesamorelin at 2 mg, and a 50 mg GLP-1 option. The tool also explains, in plain terms, why adding more BAC water to a vial changes the units you draw without changing the actual dose delivered. That point confuses a lot of beginners. The calculator is built by FormBlends, a company that also runs a 503A compounding pharmacy, so there is a real business accountable for the accuracy of this tool. The same calculator lives inside the FormBlends iOS and Android app, which adds a 55-compound reference library, dose logging, and an injection-site rotation tracker. For anyone who wants to verify the math themselves, the formula is right there on screen.
2. PeptideFox
PeptideFox at peptidefox.com covers more than 30 individual peptides and pairs its calculator with a visual guide to reconstitution. Its standout feature is optimizing the BAC water volume to produce clean, round unit draws on a standard insulin syringe. That is genuinely useful. Ugly draws like 13.7 units introduce room for error. Getting to a clean 10 or 20 units is worth the extra BAC water math.
3. PeptideDeck
PeptideDeck keeps things minimal. Enter the vial size in mg, how much BAC water you added in mL, and your target dose in mcg. It outputs the concentration and tells you how many units to draw. Nothing extra. If you want a fast answer without a tutorial, this is a reasonable choice. No app, no presets, just the core calculation.
4. MyPeptideMatch
MyPeptideMatch is free and specifically names BPC-157, semaglutide, tirzepatide, and TB-500 in its compound coverage. The semaglutide and tirzepatide support is worth noting because GLP-1 class dosing has its own quirks around concentration and titration that trip up a lot of first-timers. Solid starting point if you are working with one of those compounds.
5. LeadWest Medical Calculator
LeadWest Medical’s tool lists retatrutide, BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, sermorelin, and GHK-Cu by name. That is a longer compound list than most single-page tools. The medical branding suggests some clinical context behind it, though you should still verify any dose you use against guidance from an actual provider.
6. Outliyr Peptide Calculator
The Outliyr calculator includes named support for BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, GHK-Cu, and compounds in the GLP-1 class. The site has a broader wellness focus, so the calculator sits within a larger editorial context. If you are someone who wants reading material alongside the math, the surrounding content may be useful. If you just want the number, the interface might feel like extra friction.
7. peptidereconstitutecalculator.com
This one is BPC-157 specific. It handles the mcg-to-units conversion on a U-100 syringe. That is a narrow scope, but BPC-157 is the most commonly reconstituted peptide among beginners, so the narrowness is not necessarily a drawback. If BPC-157 is the only thing you are working with right now, this gets the job done without distraction.
8. peptides.org Dosage Charts
peptides.org takes a reference approach rather than a calculator approach. Static dosage charts, compound-by-compound. No inputs, no outputs. The value here is context: understanding typical dosing ranges for different compounds before you ever pick up a syringe. Pair it with an actual calculator for the final math.
9. Prime Peptides Calculator
Prime Peptides offers a reconstitution calculator alongside its product catalog. The functionality covers the standard inputs and outputs. Worth knowing that this tool exists within a commercial context, so treat it as one reference among several rather than a standalone authority.
10. Manual Calculation (Know the Formula)
Every tool on this list does the same arithmetic. Concentration (mcg/mL) equals total peptide in mcg divided by BAC water added in mL. Units to draw equals your target dose in mcg divided by concentration, multiplied by 100 for a U-100 syringe. Writing this down once and keeping it next to your workspace costs nothing and means you can double-check any calculator output in thirty seconds.
How to Choose
If you want the most complete free tool with visible math and multi-syringe support, FormBlends Peptide Calculator covers the most ground. If you are only working with BPC-157, the dedicated single-compound calculator is fine. If you want compound-specific context for GLP-1 class peptides, MyPeptideMatch or Outliyr are reasonable. For any tool you use, enter your numbers, check the output against the manual formula above, and confirm your dose with whoever prescribed it.
A note before you inject anything: none of these tools prescribe doses. They measure what you tell them to measure. Reconstitution calculators are arithmetic aids, not medical guidance. Work with a qualified provider for any dosing decision.
Common Questions
Does adding more BAC water to a vial change the actual dose you receive?
No, it does not. Adding more bacteriostatic water changes the concentration, which changes how many units you draw, but the total peptide in the vial stays fixed. If you reconstitute a 5 mg BPC-157 vial with 2 mL instead of 1 mL, you draw twice as many units to get the same dose. Tools like FormBlends explain this directly on screen.
Why do GLP-1 calculators like MyPeptideMatch handle semaglutide differently from peptides like BPC-157?
GLP-1 compounds such as semaglutide and tirzepatide involve titration schedules, meaning the dose increases over weeks, so the concentration-to-units math changes repeatedly across a single vial. BPC-157 is typically dosed at a fixed mcg amount. MyPeptideMatch accounts for that variable-dose structure, which a generic calculator may not handle cleanly.
What makes the FormBlends calculator more trustworthy than an anonymous single-page tool?
FormBlends is a named company operating a 503A compounding pharmacy, which means it carries real regulatory and legal accountability for the accuracy of its tools. Anonymous pages have no identifiable organization behind them. That does not mean an anonymous tool is wrong, but it does mean there is no one to hold responsible if the math is off.
If I only use U-100 insulin syringes, do I need a calculator that also supports U-50 or U-40?
Probably not right now, but supply chains shift. A U-50 syringe holds the same 0.5 mL per 50 units, so the multiplier in the formula changes from 100 to 50. If you ever switch syringe types mid-vial without adjusting your math, you will draw half or double your intended dose. FormBlends and PeptideFox both support multi-syringe selection as a safeguard against that exact scenario.
Is peptidereconstitutecalculator.com reliable enough for everyday use if I only work with BPC-157?
It handles the core mcg-to-units math for BPC-157 on a U-100 syringe, which is what most beginners need. The limitation is that it does nothing else, so if your compound list ever expands, you will need a different tool. For single-compound beginners, it is a reasonable starting point, but cross-checking its output against the manual formula takes thirty seconds and is worth doing.
Sources
- U-100 syringe specification: standard insulin syringe labeling (100 units per 1 mL)
- BPC-157 and TB-500 typical research dosing ranges: peptides.org dosage reference charts
- PeptideFox feature description: peptidefox.com (publicly accessible, 2025)
- FormBlends calculator features: FormBlends web tool and app documentation (publicly accessible, 2025)
- MyPeptideMatch compound list: mypeptidematch.com (publicly accessible, 2025)
- LeadWest Medical calculator compound list: LeadWest Medical website (publicly accessible, 2025)
