Different products can have different source values
Do not infer a concentration from a compound name, vial size or a previous calculation. This page uses only the mass, volume and target amount you enter. Verify those quantities against your actual source information.
The mass buttons are arithmetic shortcuts, not a catalogue of available preparations. Do not add water to an already-prepared solution just to match an example. The calculator does not establish whether a formulation should be reconstituted.
Use mg and mcg consistently
A known 0.25 mg amount and 250 mcg describe the same mass. Switching the target field between these units preserves that mass. The vial field remains in mg; the volume field remains in mL.
If concentration is documented directly in mg/mL, check that any mass and volume you enter reproduce that documented concentration before relying on the arithmetic.
30 mg and other vial mass inputs
A 30 mg mass does not determine how much water to add or what target amount to enter. Keep different mass inputs on this page and supply the volume from verified source instructions.
Use the reverse calculator only when you already have a target concentration or a target amount and corresponding U-100 mark.
Make the units explicit
FDA has documented medication errors involving confusion between mg, mL and units in compounded injectable products. This calculator therefore displays the mass, concentration, mL and U-100 scale together. Its result is not a prescription or confirmation that an input is clinically appropriate.
Questions about this calculator
Does this provide a Tirzepatide dose schedule?
No. Enter a target amount from your verified instructions; this calculator supplies only the arithmetic conversion.
Does a larger syringe change the concentration?
No. Capacity alone does not change concentration or U-100 units per mL. It only changes the maximum volume that the selected syringe can contain.