What is My Metformin Dose? 2026 Dosage Calculator for Diabetes

Metformin is the most prescribed diabetes medication worldwide. Our calculator helps you find the right dose based on formulation, treatment week, and side effect tolerance.

Week	Immediate-Release (IR)	Extended-Release (ER)
Week 1	500 mg once daily	500 mg once daily
Week 2	500 mg twice daily	1000 mg once daily
Week 3	1000 mg AM + 500 mg PM	1500 mg once daily
Week 4+	1000 mg twice daily (max 2000-2550 mg)	2000 mg once daily (max)

📐 2026 ADA Guidelines

Starting dose: 500 mg once or twice daily with meals

Titration: Increase by 500 mg every 1-2 weeks as tolerated

Maximum: IR 2550 mg/day (850 mg three times daily or 1000 mg twice daily)

ER maximum: 2000 mg once daily

Renal adjustment: eGFR 30-45: maximum 1000 mg/day

❓ Frequently Asked Questions About Metformin

What is the correct metformin starting dose?

The typical metformin starting dose is 500 mg once daily or 500 mg twice daily with meals. For extended-release (ER), start with 500 mg once daily. The dose is gradually increased over 1-2 months to minimize GI side effects. Maximum dose is 2000-2550 mg daily depending on formulation.

How do I titrate metformin?

Metformin titration schedule: Week 1: 500 mg once daily. Week 2: 500 mg twice daily. Week 3: 1000 mg morning, 500 mg evening. Week 4: 1000 mg twice daily (max dose). Increase dose every 1-2 weeks as tolerated. Take with meals to reduce nausea. Extended-release can be titrated faster.

What is the maximum metformin dose?

Maximum daily dose: Immediate-release: 2550 mg (850 mg three times daily or 1000 mg twice daily). Extended-release: 2000 mg once daily. Do not exceed these doses due to increased risk of lactic acidosis. Elderly patients and those with kidney issues may need lower maximum doses.

What are the side effects of metformin?

Common side effects: nausea, diarrhea, stomach upset, loss of appetite, metallic taste. These usually improve over time and with food. Serious but rare: lactic acidosis (symptoms: muscle pain, trouble breathing, stomach pain, dizziness). Stop metformin and seek medical help if you have these symptoms.

Should I take metformin with food?

YES! Always take metformin with meals to reduce GI side effects. Taking with food can significantly decrease nausea and diarrhea. If you miss a dose, take it with your next meal. Do not double up. Extended-release should be taken with the evening meal.

What is the difference between metformin and metformin ER?

Metformin immediate-release (IR) is taken 2-3 times daily and may cause more GI side effects. Metformin extended-release (ER/XR) is taken once daily, has fewer side effects, and is better tolerated. Both are equally effective. ER is often preferred for patients who can't tolerate IR.

Can I take metformin for weight loss?

Metformin is not FDA-approved for weight loss, but it may cause modest weight loss (2-5 lbs) in some people. It's primarily for diabetes and insulin resistance. For prediabetes or PCOS, doctors may prescribe it off-label. Discuss weight loss goals with your doctor.

What should I avoid while taking metformin?

Avoid excessive alcohol (increases lactic acidosis risk). Tell your doctor before contrast dye procedures (CT scans with contrast) - metformin may need to be temporarily stopped. Monitor kidney function regularly. Avoid other medications that may affect kidney function without consulting doctor.

⚠️ CRITICAL MEDICAL DISCLAIMER

NOT MEDICAL ADVICE: This metformin dosage calculator is for EDUCATIONAL AND INFORMATIONAL PURPOSES ONLY. It does not constitute medical advice and should not replace professional medical judgment. Always consult your healthcare provider before starting or changing any medication.

KIDNEY FUNCTION: Metformin requires adequate kidney function. Regular monitoring of eGFR is essential. Do not use if eGFR is below 30 mL/min.

LACTIC ACIDOSIS RISK: Metformin can cause a rare but serious side effect called lactic acidosis. Symptoms include muscle pain, trouble breathing, stomach pain, dizziness. Seek emergency care immediately if these occur.

PRESCRIPTION ONLY: Metformin is a prescription medication. It should only be used under medical supervision.

EMERGENCY CONTACT: If you suspect an overdose or have severe symptoms, call Poison Control: 1-800-222-1222 or 911.

Last Update: March 10, 2026 | Next Review: October 1, 2026

What is My Metformin Dose? 2026 Dosage Calculator for Diabetes

How This Metformin Dosage Calculator Works

💊 Metformin Types

📋 Important Precautions

📐 2026 ADA Guidelines

❓ Frequently Asked Questions About Metformin

⚠️ CRITICAL MEDICAL DISCLAIMER