The single compound calculator is the foundation of every calculation in this library. Enter your vial size, reconstitution volume, and target amount — it returns the exact volume to draw. All other calculators build on this same core logic.
How It Works
The calculator divides your vial amount by your reconstitution volume to establish concentration. It then divides your target amount by that concentration to return a draw volume in both mL and insulin syringe units.
Vial amount: 5 mg
Reconstitution volume: 2 mL
Concentration: 2.5 mg/mL
Target amount: 0.5 mg
Result: 0.20 mL → 20 units on a U-100 syringe
The Three Inputs
Every entry requires three values: your vial amount (from the label), your reconstitution volume (BAC water added), and your target amount. All three must use the same unit — mg or mcg — throughout.
Mismatched units across fields are the leading cause of incorrect results. If your vial is labeled in mg, your target must also be entered in mg.
Reconstitution Volume and Draw Size
More BAC water lowers concentration and increases draw volume. Less BAC water raises concentration and shrinks draw volume. If your result is coming back under 5 units on a U-100 syringe, increasing your reconstitution volume will give you a more readable draw.
See the BAC Water & Concentration guide for a full breakdown of how this relationship works.
Reading the Output
Results are shown in mL and in U-100 insulin syringe units. The unit figure assumes a standard 100-unit insulin syringe — 1 unit equals 0.01 mL. If you are using a different syringe type, use the mL figure instead.
See the Syringe Units guide for syringe type differences and how to read barrel markings accurately.
When to Use a Different Calculator
Use this calculator for any single-compound, single-vial entry. If your research entry combines two compounds in one draw, use the Blend Calculator. If you are modeling how amounts build across multiple intervals, use the Accumulation Calculator.
Quick Reference
Concentration = Vial amount ÷ Reconstitution volume
Draw volume (mL) = Target amount ÷ Concentration
Syringe units = Draw volume × 100 (U-100 only)
All inputs must share the same unit (mg or mcg)
Recalculate any time vial or BAC water volume changes
Common Mistakes
Standardize to one unit before entering. To convert mcg to mg, divide by 1000.
Any BAC water change updates concentration. Re-enter and recalculate before drawing.
Unit display is U-100 only. Use the mL output for other syringe types.
This guide is for research-use calculator education only. It does not provide medical advice, treatment recommendations, or personalized dosing instructions.