Semaglutide Calculator
This free semaglutide dosage calculator converts your vial strength, bacteriostatic (BAC) water volume, and weekly dose into the exact injection volume (mL) and syringe units (U-100) you need to draw. Enter your values below to calculate concentration, per-injection volume, and syringe markings instantly.
— mL
How to Use the Semaglutide Dosage Calculator
- Select your vial strength (commonly 2 mg, 5 mg, or 10 mg).
- Select how much BAC (bacteriostatic) water you added to reconstitute the vial.
- Choose your prescribed weekly dose in mg. Choose your injection frequency (once or twice weekly).
- Select your syringe type (1 mL/100-unit or 0.5 mL/50-unit).
- Click Calculate Dose to see your concentration (mg/mL), injection volume (mL), and syringe units.
What Is Semaglutide?
Semaglutide is a GLP-1 receptor agonist originally developed by Novo Nordisk for type 2 diabetes management (brand name Ozempic) and later approved for chronic weight management (brand name Wegovy). It mimics the naturally occurring glucagon-like peptide-1 hormone, which slows gastric emptying, increases satiety, and improves insulin sensitivity.
Semaglutide is available in three FDA-approved forms:
- Ozempic — weekly injection, up to 2.0 mg, approved for type 2 diabetes
- Wegovy — weekly injection, up to 7.2 mg (as of the March 2026 FDA approval), approved for chronic weight management
- Rybelsus — daily oral tablet, up to 14 mg, approved for type 2 diabetes
- Wegovy oral tablet — daily pill, up to 25 mg, approved December 2025 for chronic weight management
Semaglutide Dosage Chart & Titration Schedule (Updated 2026)
Semaglutide dosing follows a gradual titration schedule — starting low and increasing every four weeks to reduce gastrointestinal side effects. As of March 2026, the FDA approved a new high-dose tier (7.2 mg, “Wegovy HD”) for eligible patients who need additional weight loss beyond the standard maintenance dose, based on results from the STEP UP trial.
| Week | Weekly Dose | Phase |
|---|---|---|
| 1–4 | 0.25 mg | Starting dose |
| 5–8 | 0.5 mg | Titration |
| 9–12 | 1.0 mg | Titration |
| 13–16 | 1.7 mg | Titration |
| 17+ | 2.4 mg | Standard maintenance |
| 21+ (if clinically indicated) | 7.2 mg | High-dose maintenance (Wegovy HD, approved March 2026) |
A clinician must confirm additional weight loss is medically appropriate before increasing beyond the standard 2.4 mg maintenance dose.
What Changed in 2026? Latest Semaglutide Research Update
March 2026: The FDA approved a new 7.2 mg weekly Wegovy dose (“Wegovy HD”) for adults with obesity, following the Phase 3b STEP UP trial published in The Lancet Diabetes & Endocrinology. Participants on the 7.2 mg dose lost an average of 20.7% of body weight over 72 weeks, compared with 17.5% on the standard 2.4 mg dose, with roughly one-third of patients achieving 25%+ weight loss.
December 2025: The FDA approved an oral tablet version of Wegovy (up to 25 mg/day) for chronic weight management, expanding options beyond the injectable and Rybelsus formulations.
Real-world prescribing data (Truveta, 2026): The large majority of new oral semaglutide for obesity patients start at the manufacturer-recommended 1.5 mg dose, with dose increases occurring roughly every 31–33 days — closely mirroring the official titration schedule.
How Semaglutide Reconstitution & Dosage Math Works
Compounded semaglutide typically ships as a lyophilized (freeze-dried) powder that must be reconstituted with bacteriostatic water before injection. The formula your calculator uses:
- Concentration (mg/mL) = Vial strength (mg) ÷ BAC water added (mL)
- Injection volume (mL) = Prescribed dose (mg) ÷ Concentration (mg/mL)
- Syringe units = Injection volume (mL) × 100 (for a standard U-100 insulin syringe)
Worked example: A 10 mg vial reconstituted with 2 mL of BAC water yields a concentration of 5 mg/mL. A 1 mg weekly dose therefore requires 0.2 mL, which reads as 20 units on a U-100 syringe.
Use our Peptide Calculator for other peptides Dosage Calculations.
“This tool is for educational purposes only and does not constitute medical advice. Always consult a licensed healthcare provider before starting, changing, or stopping any medication.”
Semaglutide Side Effects and Safety Considerations
The most commonly reported side effects are gastrointestinal: nausea, diarrhea, constipation and vomiting, particularly during dose increases. These typically diminish as the body adjusts. Less common but more serious risks include gallbladder problems, pancreatitis and per FDA boxed warning a potential risk of thyroid C-cell tumors observed in rodent studies. Semaglutide should only be used under the supervision of a licensed healthcare provider who can evaluate personal risk factors, drug interactions and appropriate titration pace.
Frequently Asked Questions
What is the starting dose of semaglutide?
The standard starting dose is 0.25 mg once weekly, given for the first four weeks to allow the body to adjust before increasing.
What is the maximum dose of semaglutide?
For Ozempic (diabetes), the FDA-approved maximum is 2.0 mg weekly. For Wegovy (weight management), the standard maximum is 2.4 mg weekly, with a newly approved 7.2 mg high-dose tier available as of March 2026 for eligible patients under physician guidance.
How many units is 0.25 mg of semaglutide?
This depends entirely on your vial’s concentration. Use the calculator above — enter your vial strength and BAC water volume to get an accurate unit reading for your specific vial.
How long does it take to reach the maintenance dose?
Most patients reach the standard 2.4 mg maintenance dose around week 17, following the four-week titration steps.
20 units of semaglutide is how many mg?
It depends on your vial’s concentration, since “units” measure volume on a syringe, not dose directly. On a U-100 syringe, 20 units equals 0.2 mL. For example, a 10 mg vial reconstituted with 2 mL of BAC water has a concentration of 5 mg/mL, so 20 units (0.2 mL) equals 1 mg. Enter your own vial strength and BAC water amount into the calculator above to get the exact mg value for your syringe reading.