Semaglutide Dosage Calculator — mg, mL & U-100 Units
This free semaglutide dosage calculator converts an amount in mg and an actual labeled liquid concentration into mL and U-100 scale units. It does not choose a treatment dose or operate a pen. Ozempic and Wegovy contain semaglutide but have different product instructions, formulations and indications.
How to Use This Calculator
Select semaglutide, enter your amount per administration and the labeled mg/mL. Add actual full-vial solution volume only if you want quantity estimates. Changing the week never changes your entered amount. This tool does not convert tablets, pen clicks or device settings.
Arithmetic verification is separate from clinical review.
This tool converts an amount you enter into liquid volume. It does not select a dose or titration schedule. Use the instructions and concentration for your actual product; it does not convert pen clicks, tablets, or powder-mixing instructions.
Select Medication
Your product and entered amount
Enter mg per administration and the labeled mg/mL, not the total mg in the container. Full-vial solution volume is optional and means liquid volume, not container capacity.
Volume calculation
Enter an amount and labeled concentration to calculate volume.
Week tracking
Recordkeeping only: changing the week or date never changes your entered amount. A future start date displays week 1.
Current Week 1
Full-Vial Supply Estimate
Enter valid amount, concentration, and full-vial solution volume to estimate supply. Values must be within the calculator’s numerical range.
Assumes a full vial now, one administration per week, no dose changes and no handling losses. Counts complete portions only. Not a refill date, shelf-life estimate, or authorization to keep a vial in use.
Titration: product-specific references
A calendar week alone does not determine a dose. Product, indication, response and tolerability matter. Ozempic and Wegovy do not share one interchangeable dosing schedule; a branded product’s label also does not establish the instructions for a compounded vial.
Retatrutide is not Mounjaro. Mounjaro contains tirzepatide; Lilly describes retatrutide as investigational. The retatrutide option provides arithmetic, not a recommended treatment schedule. References checked September 8, 2026.
Semaglutide Titration Schedule
Ozempic prescribing information, sections 2.1–2.2: injection starts at 0.25 mg weekly for four weeks, then 0.5 mg. Later increases depend on the indication and clinical need; 2.4 mg is not the Ozempic schedule.
Wegovy prescribing information, sections 2.2–2.4: injection escalation uses 0.25, 0.5, 1 and 1.7 mg at four-week steps; intolerance may delay escalation. Adult weight-loss maintenance is 1.7 or 2.4 mg. A later 7.2 mg dose is an option only after at least four weeks tolerating 2.4 mg when additional weight reduction is clinically indicated. Other indications and oral products have different instructions.
These are product references, not a personal schedule. The calculator uses your entered amount rather than choosing one from the calendar. References checked October 2, 2026.
How to Calculate Semaglutide Injection Units
For a liquid vial, an amount in mg can be converted to mL using its labeled concentration. Brand-name delivery devices vary; use the instructions for the exact presentation rather than assuming every pen has a dose display or selector.
Brand-Name Semaglutide (Ozempic/Wegovy Pens)
Devices differ. A dial-based pen and a fixed-dose injector do not have interchangeable operating instructions. Follow the instructions for the exact supplied presentation; the calculator does not select pen settings or support extracting liquid from a pen.
Compounded Semaglutide (Vials)
Units = Dose (mg) ÷ Concentration (mg/mL) × 100
(U-100 means 100 scale units per mL, not 100 graduation lines. The result does not establish a syringe’s capacity or measurement precision.)
Example Calculations
- 0.5 mg dose with 3.33 mg/mL concentration: 0.5 ÷ 3.33 × 100 ≈ 15.015 U-100 units (about 0.15015 mL)
- 1 mg dose with 5 mg/mL concentration: 1 ÷ 5 × 100 = 20 units
- 2.4 mg dose with 3 mg/mL concentration: 2.4 ÷ 3 × 100 = 80 units
Check the vial concentration and syringe type each time the supplied product changes. Ask the dispensing pharmacist to confirm how the prescribed amount maps to your syringe. The FDA dosing-error alert describes overdoses from confusion between mg, mL and units; a correct formula cannot verify the label or syringe you have.
Compounded vs Brand-Name Semaglutide Dosing
Compare the exact product, formulation, concentration and instructions—not just the ingredient name. A compounded preparation is not automatically interchangeable with a branded product. Semaglutide sodium and acetate are different active ingredients from the base form in approved products; see the FDA ingredient and concentration notes.
Brand-Name Semaglutide (Ozempic/Wegovy)
- Product-specific devices and instructions; not every pen has a dial or dose window
- Approved products have product-specific clinical evidence and prescribing information, linked above
- Supplied devices have their own instructions; do not use a vial calculation to select pen settings
- Actual cost depends on coverage, dose and savings eligibility. Check current Ozempic manufacturer offers and terms; list price is not every patient's cash price
- Confirm local stock with the pharmacy; local availability and a national shortage designation are different
Compounded Semaglutide (Vials)
- Compare a written all-in quote: medication quantity, visit fees, shipping, supplies and refill charges
- Patient-specific compounding can address an individual need when applicable requirements are met; it is not unrestricted customization
- Concentrations may differ between products or refills; the same number of syringe units can contain a different mg amount
- Vial instructions should identify the prescribed amount, concentration, volume and appropriate syringe
- Confirm the dispensing pharmacy and the supplied product's storage and beyond-use instructions
- Compounded products do not undergo FDA premarket review for safety, effectiveness or quality
The current FDA compounding update explains separate 503A and 503B conditions. Under 503A, a prescriber-documented change producing a significant difference for an identified patient can matter to the essentially-copy restriction. Semaglutide's national injection shortage was resolved in 2025; that is separate from occasional local stock problems.
Managing the Transition Between Doses
Tolerability varies. Use your follow-up visit to discuss symptoms, intake and treatment response before the next planned increase. A higher calendar week does not mean the dose must increase.
The First Few Days After a Dose Increase
In a pooled analysis of STEP 1–3 trials, gastrointestinal events with semaglutide 2.4 mg were most common during or shortly after escalation. Most were mild-to-moderate and transient, but 4.3% of semaglutide participants permanently stopped for gastrointestinal events. These trial findings do not set a personal day-by-day symptom schedule.
Dietary Strategy During Transitions
The manufacturer's nausea guidance suggests eating slowly, trying bland lower-fat foods such as rice or toast, and avoiding greasy meals and lying down after eating. These are symptom-management suggestions, not a mandatory three-day diet or a guarantee of relief. Discuss persistent symptoms and hydration with your care team.
When to Contact Your Doctor
Do not wait seven days for concerning symptoms. Contact your clinician promptly for persistent vomiting or diarrhea, difficulty keeping fluids down, or symptoms that bother you or do not improve. Stop the medication and seek medical help immediately for severe abdominal pain that does not go away, with or without vomiting; it may radiate to the back. See the Ozempic Medication Guide for pancreatitis and dehydration warnings.
Stabilization Phase
There is no universal day when symptoms stop or benefits begin after an increase. The STEP analysis found that weight loss was largely independent of gastrointestinal adverse events: nausea is not a requirement for benefit. Review weight or glucose trends and tolerability over time with your prescriber rather than judging effectiveness from one symptomatic week.
Frequently Asked Questions
Ozempic injection and Wegovy injection start at 0.25 mg subcutaneously once weekly for four weeks. This is not an oral semaglutide schedule. The calculator uses the amount you enter; it does not prescribe a starting dose.
Schedules differ by product and indication. Wegovy injection includes a 1.7 mg escalation step; maintenance and any later increase depend on the indication and tolerability. Ozempic has its own schedule. Follow the linked prescribing information and your prescription, not a calendar-generated dose.
The liquid-volume formula works from an entered mg amount and concentration. It does not make Ozempic and Wegovy dosing equivalent, convert pen clicks, or replace device instructions. Do not extract medication from a pen using this calculator.
Instructions depend on the exact presentation: branded semaglutide is not limited to one pen design, and oral products are not liquid-volume equivalents. A compounded vial may have a different labeled concentration. Follow the supplied product instructions; the calculator does not set a device dose or establish interchangeability.
Divide mg by mg/mL to get mL, then multiply by 100 for U-100 units. At 3.33 mg/mL, 0.5 mg ÷ 3.33 mg/mL is approximately 0.15015 mL, or 15.015 U-100 units—not 50 units.
Do not accelerate escalation or choose a restart amount from this calculator. Missed-dose instructions differ: use the Ozempic label section 2.1 or Wegovy label section 2.4 linked above. After two or more consecutive missed Wegovy injections, its current label calls for restarting escalation at a lower dose; ask your prescriber which dose to use.
Related Guides & Resources
Medical Disclaimer
This dosage calculator is for educational purposes only and does not replace medical advice from your healthcare provider. Always follow your doctor's prescribed dosing schedule. If you experience severe side effects, have questions about your semaglutide regimen, or believe you're having an adverse reaction, contact your physician immediately. Do not adjust your dose without explicit medical guidance.