Core feature
Peptide Calculator: Math-Free Reconstitution
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
- 12+ pre-loaded peptide profiles — 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 12+ pre-loaded peptide profiles (BPC-157, TB-500, semaglutide, tirzepatide, ipamorelin, and more), 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.