PeptideCalculations

Vial and water tables

Every cell is the concentration that vial and water volume produce. Open a cell for the full table: mL and units for each amount per draw, draws per vial, and what changes if you add a different volume.

Vial0.5 mL1 mL1.5 mL2 mL2.5 mL3 mL5 mL
1 mg2 mg/mL1 mg/mL0.67 mg/mL0.5 mg/mL0.4 mg/mL0.33 mg/mL—
2 mg4 mg/mL2 mg/mL1.33 mg/mL1 mg/mL0.8 mg/mL0.67 mg/mL—
3 mg6 mg/mL3 mg/mL2 mg/mL1.5 mg/mL1.2 mg/mL1 mg/mL0.6 mg/mL
5 mg10 mg/mL5 mg/mL3.33 mg/mL2.5 mg/mL2 mg/mL1.67 mg/mL1 mg/mL
10 mg20 mg/mL10 mg/mL6.67 mg/mL5 mg/mL4 mg/mL3.33 mg/mL2 mg/mL
15 mg30 mg/mL15 mg/mL10 mg/mL7.5 mg/mL6 mg/mL5 mg/mL3 mg/mL
20 mg40 mg/mL20 mg/mL13.33 mg/mL10 mg/mL8 mg/mL6.67 mg/mL4 mg/mL
30 mg—30 mg/mL20 mg/mL15 mg/mL12 mg/mL10 mg/mL6 mg/mL
50 mg—50 mg/mL33.33 mg/mL25 mg/mL20 mg/mL16.67 mg/mL10 mg/mL
60 mg—60 mg/mL40 mg/mL30 mg/mL24 mg/mL20 mg/mL12 mg/mL

Dashes mark pairs that do not fit a real vial (half a millilitre in a 30 mg vial, 5 mL in a 1 mg vial). The calculator accepts any numbers.

Reading the grid

Across a row the vial mass is fixed and the water increases, so the concentration falls and every draw needs more units. Down a column the water is fixed and the mass increases, so the concentration rises and every draw needs fewer units. A 5 mg vial with 2 mL and a 10 mg vial with 4 mL sit at the same concentration, 2.5 mg/mL, and give identical unit counts; the second vial simply holds twice as many draws.

Pick a volume that gives round numbers. At 2.5 mg/mL every 100 mcg is 4 units on a U-100 syringe. At 5 mg/mL (5 mg in 1 mL, or 10 mg in 2 mL) every 100 mcg is 2 units, and a 0.3 mL barrel still covers amounts up to 1.5 mg. The water calculator works backwards from the unit count you want.