A free, data-driven calculator for GLP-1 medications
GLP1Calc is a free online tool that helps people understand what to expect from GLP-1 weight loss medications including Ozempic, Wegovy, Mounjaro, and Zepbound. It provides two calculators: a weight loss predictor based on real clinical trial data, and a dosing schedule guide showing standard dose escalation timelines.
Our weight loss estimates are based on published clinical trial results — specifically the STEP trials (semaglutide) and SURMOUNT trials (tirzepatide). These are the same studies used by health authorities to approve these medications.
Dosing schedules reflect the standard approved escalation protocols for each medication. Individual prescriptions may vary — always follow your doctor's guidance.
Every article on GLP1Calc is written against primary sources: the original published clinical trials, approved prescribing information, and peer-reviewed literature. We do not publish anecdote as fact or cite secondary sources without cross-checking the underlying data.
Our specific sources include the STEP 1–5 trials (semaglutide 2.4 mg, published in the New England Journal of Medicine), the SURMOUNT 1–4 trials (tirzepatide, published in NEJM and JAMA), and the 2025 SURMOUNT-5 head-to-head trial. Dosing information reflects FDA-approved prescribing information.
Articles are reviewed for factual accuracy before publication and updated when new data emerges. If you spot an error or have a correction, email us — we take accuracy seriously.
GLP1Calc is for informational purposes only. It does not constitute medical advice and is not a substitute for professional healthcare guidance. All GLP-1 medications require a prescription from a licensed healthcare provider. Always consult your doctor before starting, changing, or stopping any medication.
Individual results vary significantly. The calculator provides estimates based on population-level clinical trial averages — your actual results will depend on your starting weight, dosing schedule, adherence, diet, exercise, and individual response to medication.
Questions, corrections, or found an error in our data? Email us at callanjotta@gmail.com — we aim to respond within 48 hours.