Dose calculator

Tirzepatide dose calculator

Convert any Tirzepatide dose into syringe units in real time, pre-filled with a 10 mg / 2 mL example.

iPhone · Free to download

Last updated: May 13, 2026

Vial (mg)

Diluent (mL)

Dose (mg)

Dose unit

Draw on a U-100 syringe

50.0 units

Volume to draw

0.500 mL

Tirzepatide is a once-a-week injection people use to lose weight and improve blood sugar control. It hits two gut-hormone receptors at once — GLP-1 and GIP — which is why it tends to drive larger appetite and weight changes than single-receptor drugs. In the SURMOUNT-1 trial, participants without diabetes lost roughly 20.9% of body weight over 72 weeks on the highest dose. This page covers reconstitution math and weekly dose logging.

How the Tirzepatide dose calculator works

Tirzepatide doses step from 2.5 mg up to 15 mg in 2.5 mg increments. On a 10 mg vial mixed with 2 mL water, that means 50 units for the starter step, 100 units at 5 mg, all the way up to 300 units at 15 mg. The calculator runs the units math each time you pick a new step.

The formula is volume in mL equals dose mg divided by concentration mg/mL, then volume times one hundred to get units on a U-100 insulin syringe. With a 5 mg/mL Tirzepatide solution and a 2.5 mg dose, the draw is 0.50 mL or about 50 units. Type any other dose and the unit count updates in real time — no spreadsheets, no guesswork.

Inputs that genuinely matter: concentration (which only changes when you reconstitute a new vial) and dose mass. Syringe type matters too, but only because U-100 vs U-40 changes the multiplier — almost every modern insulin syringe is U-100, which is why the math defaults to that. Edge cases worth flagging: switching from mcg to mg without checking the input unit, or carrying yesterday's unit count over to a new vial that was reconstituted with a different volume of BAC water.

Worked example

Walking one Tirzepatide dose through the math

The vial holds 10 mg of Tirzepatide, mixed into 2 mL of bacteriostatic water — concentration 5.00 mg/mL.
Your 2.5 mg dose ÷ 5.00 mg/mL = 0.500 mL of solution to pull.
Multiply by 100 (because U-100 means 100 units per mL): 0.500 × 100 = 50 units.
Double the dose to 5 mg and the unit count doubles to 100 — the relationship is linear at a fixed concentration.
Change the diluent volume and every one of these numbers moves; change the dose alone and only the last one does.

Tirzepatide titration ladder at this concentration

What different Tirzepatide dose steps draw on a U-100 insulin syringe at the example 5.00 mg/mL concentration.

Dose (mg)	Volume (mL)	Units (U-100)
1.25	0.250	25
2.5	0.500	50
5	1.000	100
10	2.000	200

Doubling the Tirzepatide dose doubles the unit count. Halving it halves the count. Step-ups under 5 units are hard to read accurately — re-reconstitute with more water if your titration hits that range.

Scenarios people actually run into

Three things that come up logging Tirzepatide

You're sitting at the 2.5 mg Tirzepatide step and your prescriber bumps you up. The new dose is double — 100 units instead of 50. Same vial, same syringe, twice the volume on the line.
Your fingers reach for the syringe and the unit count from last week is still in your head. Half the time that number is fine; the other half, the vial changed and the right answer moved. The calculator is the second pair of eyes.
You skipped a week. Tirzepatide cadence is 1 dose per week, and doubling up to "catch up" almost never reads how people expect — log the skip, then log the next normal dose.

Same-category neighbor

Tirzepatide next to Liraglutide

Both sit in the GLP-1 bucket — here's the dose math side by side on each one's example vial.

	Tirzepatide	Liraglutide
Example dose	2.5 mg	1.2 mg
Concentration	5.00 mg/mL	2.00 mg/mL
Units to draw	50	60

Want the full breakdown? Liraglutide reference →

How Tirzepatide dosing is tracked

Weekly subcutaneous injection is the default. Each draw is small enough that almost everyone uses a U-100 insulin syringe rather than a tuberculin syringe.

Tirzepatide protocols often involve gradual dose escalation over months, starting low and increasing every several weeks to reduce gastrointestinal side effects. Logging that escalation in real time — including the exact date and unit count of each step — is what makes the pattern auditable months later.

Vial-aware tracking is especially helpful for tirzepatide because the same vial can support many doses across a long stretch of weeks. Knowing exactly how many doses remain prevents the awkward case of opening a fresh vial and finding that the previous one still had several usable draws left.

Published research protocols for tirzepatide frequently describe a multi-step dose titration schedule that can span five months or longer. A widely studied pattern involves initiating at a 2.5 mg weekly dose and escalating monthly through subsequent tiers: 5 mg, 7.5 mg, 10 mg, 12.5 mg, and a final tier of 15 mg. For researchers documenting their work, this dose-stepping creates a significant planning challenge. To accurately observe such a protocol, one must schedule six discrete dosage levels over the course of the study, each requiring its own precise volume calculation prior to administration.

Common Tirzepatide dose-calculation mistakes

Skipping the escalation date in the log, then being unable to answer when a dose change actually happened.
Failing to recalculate the correct unit volume for each new dose during a multi-step titration schedule.
Attempting to draw a volume greater than 1 mL, such as 1.5 mL or 3 mL, into a standard 1-mL insulin syringe.

Frequently asked questions about Tirzepatide dose calculator

How does the Tirzepatide dose calculator turn mg into syringe units?

It runs two divisions in sequence. First it computes concentration (vial mg ÷ diluent mL) — for the example here that's 10 ÷ 2 = 5.00 mg/mL. Then it divides your dose by that concentration to get volume in mL, and multiplies by 100 to convert volume into U-100 syringe units. The output updates as you type so you can sanity-check before drawing. Tirzepatide titration in the SURMOUNT trials moved every 4 weeks, so a 10 mg vial often covers a single titration step.

Does the Tirzepatide dose calculator know which syringe I'm using?

It assumes a U-100 insulin syringe — the most common type for sub-cutaneous peptide injections. U-100 means 100 units per mL. If you're using a U-40 syringe (rare outside veterinary contexts) the unit count is wrong by a factor of 2.5. Tuberculin syringes read in mL directly, so on those just use the volume figure. Tirzepatide titration in the SURMOUNT trials moved every 4 weeks, so a 10 mg vial often covers a single titration step.

Why does the same Tirzepatide dose pull a different unit count today than last week?

Because either the vial or the diluent volume changed. Concentration depends on both. A 5 mg vial reconstituted with 1 mL is twice as concentrated as the same vial with 2 mL — same dose, half the units. Whenever you open a fresh vial, run the dose math again rather than carrying the prior count over. Tirzepatide titration in the SURMOUNT trials moved every 4 weeks, so a 10 mg vial often covers a single titration step.

What if my Tirzepatide dose lands at fewer than 5 units?

That's the calculator telling you the current vial is too concentrated for the dose you want. Five units on a U-100 syringe is hard to read accurately — the markings get tight. Reconstitute the next vial with more bacteriostatic water (commonly 2 mL instead of 1 mL) so each dose covers a larger, cleaner volume. Tirzepatide titration in the SURMOUNT trials moved every 4 weeks, so a 10 mg vial often covers a single titration step.

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