Pindrop

Vial Longevity Calculator

See how many injections a vial holds, how many weeks it lasts, and how much you lose to needle dead space along the way.

mL
mg/mL
mg

Injections per week

mL

~0.04 standard, ~0 low-dead-space.

$

Optional.

This vial lasts

12weeks

24 injections from a 10 mL vial
Per injection
0.375mL
Total injections
24
Lost to dead space
192 mg(9.6%)

What this calculator does

Running out of a vial sooner than expected usually comes down to two things: the real per-injection volume, and the small amount left behind in the needle each time. This calculator accounts for both, so you know how many shots a vial actually gives and when to reorder before you are caught short.

Enter the vial size in milliliters, the concentration, your weekly dose, and how often you inject. Dead space is the liquid trapped in the needle hub that gets discarded with each injection, roughly 0.04 mL for a standard needle and close to zero for a low-dead-space one. Add a vial price and you also get a cost per week.

Reading the result

The headline is how many weeks the vial covers, with the total injection count beside it. The stat row breaks down the volume per injection and the amount lost to dead space, shown in both milligrams and percent, which is often larger than people expect over a full vial. If each dose needs more than a full syringe, a warning suggests checking your dose and concentration.

Common questions

How long will my vial last?
Divide the total drug in the vial by your dose per injection to get the number of shots, then match that to your schedule. A 10 mL vial at 200 mg/mL holds 2000 mg, so at 100 mg a week that is 20 weeks. Dead space in the syringe shaves a little off the real total.
How many doses are in a 10 mL vial?
It depends on your dose. A 10 mL testosterone vial at 200 mg/mL has 2000 mg total, so it is 20 doses at 100 mg or 40 doses at 50 mg. Divide the total mg by your per-dose mg to get your own number.
What is syringe dead space?
Dead space is the liquid left in the needle and hub after you push the plunger all the way down. That small amount, often 0.05 to 0.1 mL per shot, never makes it into you and gets thrown away with the syringe. Over many injections it adds up to real waste.
What are low dead space syringes?
They are syringes built so almost no liquid stays trapped in the hub and needle after you inject. Insulin syringes with a fixed needle are naturally low dead space. Using them means more of each vial reaches your body and less gets wasted.
How do I reduce wasted medication?
Use low dead space syringes like insulin syringes, and avoid overdrawing then squirting the excess back, which wastes product and adds air. Getting every last bit matters most with small or expensive vials. A longevity calculator that includes dead space shows you the real dose count.

Pindrop is a calculation tool, not medical advice. Confirm your dose and protocol with a licensed healthcare provider.