THE MATH, EXPLAINED

Every number has a formula.

The calculator uses dimensional arithmetic. It cannot verify vial contents, determine a dose, or assess whether a preparation is appropriate for use.

1. Normalize the target amount

When the target is entered in micrograms, divide it by 1,000 to obtain milligrams.

Target mg = target mcg ÷ 1,000

2. Calculate concentration

Concentration (mg/mL) = vial mass (mg) ÷ final volume (mL)

3. Calculate the target volume

Target volume (mL) = target mass (mg) ÷ concentration (mg/mL)

4. Convert to a U-100 scale

U-100 units = target volume (mL) × 100

This conversion is for the U-100 scale only. Units here represent syringe volume markings, not a universal measurement of peptide activity.

A worked arithmetic example

For a hypothetical vial containing 10 mg in a final volume of 2 mL, concentration is 5 mg/mL. A user-specified target of 250 mcg is 0.25 mg. Dividing 0.25 mg by 5 mg/mL gives 0.05 mL, equivalent to 5 U-100 units. There are theoretically 40 complete target amounts in the vial.

This example demonstrates arithmetic only and is not a suggested dose or preparation.

Final volume and other assumptions

The formula uses final solution volume. The volume of liquid added is only equivalent if any change in volume from dissolving the material is negligible. Use the final volume specified by your validated instructions; the calculator cannot establish this assumption for your preparation.

Other assumptions include complete dissolution, uniform concentration, and an accurate statement of vial mass. No allowance is made for purity, losses, residual liquid, degradation, storage limits, or measurement uncertainty.

Precision and capacity

Results are shown to up to six significant digits. This is display precision, not a guarantee of measurement accuracy. The illustrated scale does not specify the smallest marking on your actual syringe. Values above the displayed 1 mL capacity are flagged; the graphic never extends past its maximum.

Complete target amounts are rounded down. Inputs must be positive, finite values. Targets larger than the vial mass are rejected.

Checking the result

Multiplying the calculated volume by concentration should recover the target mass. Independently verify inputs, unit conversions, and measurement feasibility with a qualified professional before use.