Most peptide calculators are anonymous HTML pages that nobody maintains. No company name, no update history, no accountability. That’s fine until you realize you’re trusting your reconstitution math to a hobbyist project that may not have been touched since 2021. A few tools on this list break that pattern. Most don’t. Here’s where each one sits.
Quick Comparison
| Tool | Syringe Types | Preset Peptides | Shows Math | Mobile App | Company Behind It |
| FormBlends Peptide Calculator | U-100, U-50, U-40 | Yes (BPC-157, TB-500, GLP-1, more) | Yes | Yes (iOS/Android) | FormBlends (503A pharmacy) |
| PeptideFox | U-100 assumed | 30+ | No | No | Anonymous |
| PeptideDeck | U-100 assumed | No (manual entry) | Partial | No | Unknown |
| MyPeptideMatch | U-100 assumed | BPC-157, semaglutide, tirzepatide, TB-500 | No | No | Unknown |
| LeadWest Medical | Unspecified | 7 named | No | No | Medical clinic |
| Outliyr | Unspecified | BPC-157, TB-500, GLP-1 class, others | No | No | Health media site |
1. FormBlends Peptide Calculator
Best overall.
What sets this one apart is surprisingly mundane: it shows you the actual arithmetic. Enter your vial size, how much bacteriostatic water you added, and the dose your provider gave you. It outputs your draw in syringe units, the concentration per mL, and the total number of doses left in the vial. Then it shows you exactly how it got there.
The reason that transparency matters is practical, not academic. The single most dangerous mistake in peptide dosing is conflating mg with mcg, a 1,000-fold error. The calculator flags that conversion explicitly, handling it automatically while making sure you understand what happened.
A few things I haven’t seen elsewhere in one free tool. It supports U-100, U-50, and U-40 syringes, not just the default U-100 that every other calculator assumes. A visual syringe fill bar shows your dose as a physical position on the barrel. One-tap presets exist for common vial sizes like BPC-157 at 5 mg or 10 mg, TB-500 at 5 mg, ipamorelin at 10 mg, and a 50 mg GLP-1 option. Works on any lyophilized peptide because the underlying reconstitution formula is universal.
The web version requires no account. The FormBlends mobile app (iOS and Android) includes the same calculator, plus a 55-compound reference library, dose logging, and an injection-site rotation map. That’s genuinely useful for multi-peptide protocols.
FormBlends operates a 503A compounding pharmacy, which means this isn’t a side project. That matters for long-term tool availability.
One honest note: the calculator does not tell you what dose to take. Its job is translating whatever your provider prescribed into the correct physical measurement on your syringe. That framing is correct, and the tool is clear about it.
2. PeptideFox
Best for peptide-specific reference.
PeptideFox covers over 30 peptides, which is the widest catalog on this list. It also optimizes suggested BAC water volumes specifically so your draw lands on a clean, readable unit mark. That’s a practical touch most calculators skip. A visual guide walks through the process. No account needed. The downside is that it doesn’t show its math, so you’re trusting the output without a way to sanity-check it.
3. PeptideDeck
Best for bare-bones math.
Simple inputs: peptide amount in mg, BAC water volume in mL, target dose in mcg. Outputs are concentration and draw volume in both mL and insulin units. No presets, no visual aids. If you already know what you’re doing and just want a quick calculation, PeptideDeck is fast. No frills at all.
4. MyPeptideMatch
Best for GLP-1 users.
Free, no login. Covers BPC-157, TB-500, semaglutide, and tirzepatide, which makes it one of the few calculators that explicitly handles GLP-1 class peptides alongside the healing peptide staples. Layout is clean. No math shown, no syringe-type options, but it gets the job done for the peptides it covers.
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5. LeadWest Medical
Best for clinic-adjacent context.
A medical clinic built this one, and it shows in the peptide list: retatrutide, BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, sermorelin, GHK-Cu. It covers compounds that purely anonymous tools often skip. The interface is plain and the math isn’t shown, but it carries slightly more institutional weight than a random domain.
6. Outliyr
Best as a reference companion.
Outliyr is primarily a health media site, and its peptide calculator reflects that. It covers BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, GHK-Cu, and GLP-1 options. Useful if you’re already reading Outliyr content and want to calculate in the same tab. On its own, it doesn’t offer anything the tools above don’t do, but the surrounding editorial context can be helpful for newer users.
FAQ
Why do different BAC water volumes give different unit draws for the same dose?
Adding more water to a vial lowers the concentration. More mL per mg means you draw more units to get the same amount of peptide. The total peptide in the vial doesn’t change. Only your draw volume changes.
What is a U-100 syringe?
A U-100 insulin syringe holds 1 mL across 100 units. So 10 units equals 0.1 mL, and 50 units equals 0.5 mL. Most peptide calculators default to U-100 because it’s the most common type in the U.S.
Can I use these calculators for any lyophilized peptide?
Yes. The reconstitution formula is the same regardless of the compound. Vial size divided by water volume gives concentration. Dividing your target dose by that concentration tells you how many mL to draw. The peptide’s name doesn’t change the math.
What’s the mg vs. mcg problem people mention?
1 mg equals 1,000 mcg. If you enter a dose in the wrong unit, your calculated draw is off by a factor of 1,000. That’s the most common and most consequential math error in peptide dosing. A good calculator handles the conversion for you and makes it visible.
Are any of these tools official medical advice?
No. Every tool on this list is a measurement aid. None of them prescribe a dose. Dosing decisions require a qualified medical provider.
Sources
- U-100 syringe unit/volume conversion: standard insulin syringe labeling specifications
- Lyophilized peptide reconstitution math: general pharmaceutical compounding reference
- PeptideFox feature descriptions: peptidefox.com (public-facing tool page)
- PeptideDeck feature descriptions: peptideckcalculator.com (public-facing tool page)
- LeadWest Medical peptide list: LeadWest Medical public calculator page
- Outliyr peptide calculator: outliyr.com public tool page
- MyPeptideMatch: mypeptidematch.com public tool page
