Help Center

Reconstitution
calculator

Arithmetic, not advice.

Enter the amount in the vial and the final volume of solution. You get the concentration and what one click of the dial delivers. Add an amount per dispense and you also get its volume and the clicks to dial.

This tool calculates from your entries. It does not choose an amount, a diluent, or a preparation method.

Total amount
mg
Final volume
mL
Concentration
mg/mL
Choose your calculation

Calculate concentration, liquid volume, and the click equivalent for a MODTECH pen.

01 Your numbers

Enter your numbers

Enter the total labeled amount. Choose the unit printed on the label.

mL

Total liquid volume after mixing, in mL. Use the final volume from your verified preparation information.

Optional. Enter an independently determined amount to calculate its liquid volume.

1 mg = 1,000 mcg. You can use different units for the two amounts. Changing a unit converts the existing value.

Liquid added can differ from final solution volume. This calculator uses final volume and does not estimate that difference.

02 Result

Your calculation

Enter the vial amount and final solution volume to see your concentration.

    Understand the limits

    Pen mode checks the MODTECH dial and cartridge limits. Vial mode calculates volume without applying pen limits. An optional U-100 conversion uses 100 scale units per mL; barrel capacity changes the display range, not the conversion. Check the actual markings on your device.

    A few useful distinctions

    What changes between pen and vial mode?

    Both use the same concentration and calculated volume. Pen mode converts that volume into MODTECH clicks and checks the dial limits. Vial mode keeps the result in mL, with an optional U-100 scale equivalent.

    Is liquid added the same as final volume?

    Not always. The calculation uses the total solution volume after mixing. If you know only the amount of liquid added, the calculator cannot determine the difference for your material.

    Does the calculator choose an amount?

    No. Enter an independently determined amount. The example only demonstrates arithmetic; it does not recommend an amount, substance, diluent, or preparation.

    Are pen clicks and U-100 units interchangeable?

    They describe different devices. The stated MODTECH click volume and one U-100 scale unit both correspond to 0.01 mL, but that numerical match does not make other pens or scales equivalent. Use the mode that matches your device.

    What do these units mean?
    mg and mcg — amount of material
    Both measure mass. One milligram (mg) equals 1,000 micrograms (mcg). They do not measure liquid volume.
    mL — liquid volume
    Milliliters describe how much liquid there is.
    mg/mL or mcg/mL — concentration
    The amount of material in each milliliter. For the same total amount, a larger final volume gives a lower concentration.
    Clicks — pen increments
    A click is one fixed step of this pen’s mechanism. The amount represented by a click depends on concentration. Clicks are not a universal unit across devices.

    Where to
    go next

    Loading the penThe full routine for filling a cartridge, venting it and priming — before the first click counts for anything. Cartridge informationGlass and stopper spec, how ours are sterilized, and how much you actually get out of a 3 mL fill. Pen modelsV2 and V3 side by side, including where the V3's design comes from. Same cartridge, same 60-click dial, and no "more accurate" model. TroubleshootingA stiff press, a drip after dispensing, or a dial that won't move — what to check, and in what order. Sterile 3mL cartridgesBorosilicate glass, 11mm stopper, steam sterilized and individually sealed. Fits MODTECH V2 and V3, plus V1-style 3mL pens. Pens and kitsEvery pen takes the same cartridge and the same 60-click dial. Pick on looks and price.

    Still stuck?

    No call center, no ticket queue. We reply within one business day.

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    MODTECH products are precision hardware sold for laboratory and research use only. They are not medical devices. No substances are included with or sold alongside any product, and nothing on this page constitutes medical advice or instructions for administering any substance to humans or animals.

    This calculator divides the numbers you enter and makes no recommendation about them.