PepSplain calculates relationships among mass, assumed liquid volume, concentration and selected syringe-scale markings using only values entered by the visitor. It does not contain a peptide selector, recommend a target amount, or validate a medical use.
1. Concentration
In the calculator, the entered vial mass is in milligrams (mg) and the entered liquid amount is in milliliters (mL). Their ratio is shown in mg/mL.
2. Mass-to-volume conversion
Once concentration is known, the volume mathematically corresponding to a user-entered mass is mass (mg) ÷ concentration (mg/mL). This is a unit conversion, not an appropriate or recommended dose.
3. Volume-to-scale conversion
For a U-100 scale, multiply volume in mL by 100; for U-40, multiply by 40. These are numbered calibration values, not the count of short tick lines on the barrel.
4. Reverse conversion
A user-entered marked-scale value can be converted to mL by dividing it by the calibration. Multiply the result by mg/mL to find the corresponding theoretical mass.
5. What the built-in warnings mean
Warning conditions flag nonpositive or missing inputs, a calculated volume greater than the entered syringe capacity, an amount greater than the vial's total mass, or a result between the selected graduation intervals. The tool cannot establish whether a syringe can measure a small amount accurately, and no warnings should be interpreted as a safety pass.
6. Important assumptions and uncertainties
- The tool assumes the final liquid volume equals the user-entered liquid volume. Dissolved material, displacement, transfer losses, or manufacturer instructions may make this inaccurate.
- It assumes the entered vial mass is accurate and available. It cannot verify purity, identity, potency, sterility, solubility or stability.
- Its theoretical full-portion count ignores all residual volume, waste, uncertainty and real-world losses.
- Intermediate calculations use floating-point arithmetic and displayed values may be rounded. Do not reverse-engineer precision from rounded display values.
- The illustration is schematic and is not to scale or a substitute for a specific syringe's printed calibration.
7. Privacy and independence
The arithmetic runs in the visitor's browser, without uploading the numbers entered into the calculator. The site uses Cloudflare Web Analytics and Google Analytics 4 to understand aggregate usage, performance, calculator engagement and navigation. Custom events do not include calculator values, entered amounts, personal information or health information. Google advertising-personalization signals are disabled. The site has no account system, advertising pixel or sign-in requirement. Hosting infrastructure may also process request and security logs. See the privacy page. The operator shares ownership with Driftless Research and the planned Daily Peptide Stack publication; these relationships are disclosed.