Core feature
Peptide Calculator: Math-Free Reconstitution
By Baris Bingor · Last updated
What is a peptide calculator and how does Peptly work?
A peptide calculator converts a lyophilized vial mass, a chosen bacteriostatic water volume, and a target dose into the exact units to draw on an insulin syringe. Peptly does this instantly: enter or load the vial (e.g. 5 mg), set BAC water (e.g. 2 ml), pick a target mass (e.g. 250 mcg), and the app shows the draw mark on a visual U-100 syringe.
How the math works
Reconstitution is two divisions, no chemistry:
- Concentration = vial mass (mg) ÷ BAC water volume (ml). A 5 mg vial in 2 ml of bacteriostatic water gives 2.5 mg/ml.
- Draw volume = target dose (mg or mcg) ÷ concentration (mg/ml). A 250 mcg dose at 2.5 mg/ml is 0.1 ml.
- U-100 units = draw volume (ml) × 100. 0.1 ml = 10 units.
Peptly does all three live as you adjust any input. The visual syringe view shows the exact unit mark so the draw is unmistakable — no squinting at tick marks while doing mental math.
Reference table — common vial sizes
| Vial | BAC water | Concentration | Example dose | U-100 units |
|---|---|---|---|---|
| 2 mg | 1 ml | 2 mg/ml | 250 mcg | 12.5 units |
| 5 mg | 1 ml | 5 mg/ml | 250 mcg | 5 units |
| 5 mg | 2 ml | 2.5 mg/ml | 250 mcg | 10 units |
| 5 mg | 3 ml | 1.67 mg/ml | 500 mcg | 30 units |
| 10 mg | 2 ml | 5 mg/ml | 500 mcg | 10 units |
| 10 mg | 5 ml | 2 mg/ml | 1 mg | 50 units |
What Peptly adds beyond a calculator
- 23 pre-loaded peptide profiles, plus add-your-own — BPC-157, TB-500, semaglutide, tirzepatide, retatrutide, ipamorelin, CJC-1295, GHK-Cu, tesamorelin, MOTS-c, NAD+, AOD-9604, and a custom-compound option.
- Visual syringe view — see the draw mark on a U-100 syringe, not just a number.
- Injection log — every shot, site, and cycle stored on-device.
- Smart reminders — schedule-aware notifications with site rotation prompts.
- Saved protocols — reload any reconstitution mix in one tap.
- CSV export — your records, your control.
- 100% on-device — no accounts, no servers, no third-party tracking.
For per-peptide references see
- BPC-157 reconstitution math
- TB-500 reconstitution math
- Semaglutide reconstitution math
- Tirzepatide reconstitution math
- Ipamorelin reconstitution math
- BAC water calculator
- How to reconstitute peptides: step-by-step
Frequently asked questions
Is the Peptly peptide calculator free? +
Yes. The reconstitution calculator is free in the Peptly iOS app. There is no account required, no subscription gate on the math, and no advertising.
What does the calculator actually compute? +
Given a vial mass (e.g. 5 mg), a bacteriostatic water volume (e.g. 2 ml), and a target dose (e.g. 250 mcg), it computes the concentration (2.5 mg/ml) and the exact units to draw on a U-100 insulin syringe (10 units). It also shows the draw mark on a visual syringe.
How is Peptly different from a generic peptide calculator app? +
Peptly has 23 pre-loaded peptide profiles (BPC-157, TB-500, semaglutide, tirzepatide, ipamorelin, and more) and lets you add any peptide that is not preloaded, supports saved reconstitution mixes you can reload in one tap, includes an injection log with site rotation, and runs entirely on-device with no cloud sync or accounts.
Does it work for semaglutide and tirzepatide? +
Yes — semaglutide, tirzepatide, retatrutide, and other GLP-1 / GIP-GLP-1 peptides are pre-loaded profiles. The math is identical to research peptides; only the typical dose mass is different.
What syringe sizes does Peptly support? +
U-100 by default (the most common in research). U-40 is available as an option in Settings for users on alternative scales.