⚠️ CRITICAL MEDICAL WARNING
This calculator is for educational and reference purposes only.
ALWAYS verify medication dosages with healthcare professionals, official prescriptions, and pharmaceutical references.
Incorrect dosage calculations can result in serious harm or death. Never rely solely on online calculators for medication dosing.
Consult your doctor, pharmacist, or healthcare provider for all medical dosage decisions.
Mcg to Mg Converter
Convert between micrograms and milligrams with medical-grade precision. Essential for medication dosages, vitamins, and laboratory measurements
Micrograms ↔ Milligrams Converter
Enter the amount in micrograms to convert to milligrams
Conversion Results
Conversion: 1 mg = 1000 mcg | 1 mcg = 0.001 mg
Formula: 0 mcg ÷ 1000 = 0 mg
Precision: Medical-grade accuracy (exact conversion)
Additional Weight Conversions
Metric Units
Grams: 0.000000000 g
Kilograms: 0.000e+0 kg
Nanograms: 0 ng
Imperial Units
Ounces: 0.000e+0 oz
Pounds: 0.000e+0 lbs
Grains: 0.000000 gr
Conversion Formulas
Micrograms to Milligrams:
mg = mcg ÷ 1000
Divide micrograms by 1000 to get milligrams
Milligrams to Micrograms:
mcg = mg × 1000
Multiply milligrams by 1000 to get micrograms
Critical: 1 mg = 1000 mcg (exact conversion). Always double-check medical calculations.
Common Medical Dosage Examples
| Micrograms | Milligrams | Medication Example | Medical Use | Category |
|---|---|---|---|---|
| 25 mcg | 0.025 mg | Levothyroxine | Thyroid hormone replacement | Endocrine |
| 50 mcg | 0.05 mg | Folic Acid | Vitamin B9 supplement | Vitamin |
| 100 mcg | 0.1 mg | Clonidine | Blood pressure medication | Cardiovascular |
| 125 mcg | 0.125 mg | Digoxin | Heart rhythm medication | Cardiovascular |
| 200 mcg | 0.2 mg | Misoprostol | Gastric protection | Gastrointestinal |
| 250 mcg | 0.25 mg | Alprazolam | Anxiety medication | Psychiatric |
| 400 mcg | 0.4 mg | Folic Acid (pregnancy) | Prenatal supplement | Vitamin |
| 500 mcg | 0.5 mg | Vitamin B12 | B12 deficiency treatment | Vitamin |
| 1000 mcg | 1 mg | Vitamin B12 (high dose) | Severe deficiency | Vitamin |
| 2500 mcg | 2.5 mg | Vitamin D3 | Vitamin D supplement | Vitamin |
Disclaimer: Examples are for educational purposes only. Always verify with healthcare professionals and official prescribing information.
Medical Mass Scale
1,000,000,000,000 mcg
1,000,000,000 mcg
1,000,000 mcg
1,000 mcg
Base unit
0.001 mcg
0.000001 mcg
Quick Reference
Safety Tips
Always verify calculations with healthcare professionals
Double-check decimal placement - mcg and mg differ by 1000x
Use official prescribing information for final dosing decisions
μg is the scientific symbol for micrograms
Critical Medication Categories
Thyroid Hormones
Examples: Levothyroxine, Liothyronine
Typical Range: 25-200 mcg
Note: Small dose changes can significantly affect thyroid function
Heart Medications
Examples: Digoxin, Warfarin
Typical Range: 125-250 mcg
Note: Narrow therapeutic window - precision prevents toxicity
Vitamins & Supplements
Examples: Vitamin B12, Folic Acid, Vitamin D
Typical Range: 50-2500 mcg
Note: Essential nutrients with specific dosing requirements
Psychiatric Medications
Examples: Alprazolam, Clonazepam
Typical Range: 250-2000 mcg
Note: Precise dosing prevents dependence and side effects
Pain Management
Examples: Fentanyl, Buprenorphine
Typical Range: 25-100 mcg
Note: Extremely potent - mcg-level precision critical for safety
Hormone Therapy
Examples: Estradiol, Testosterone
Typical Range: 50-200 mcg
Note: Hormone balance requires precise microgram dosing
Understanding Micrograms and Milligrams
What are Micrograms and Milligrams?
Both micrograms (mcg or μg) and milligrams (mg) are metric units of mass. They differ by a factor of 1000, making precise conversion critical in medical applications.
Why Micrograms Matter
- •Many medications are potent in microgram doses
- •Vitamins and hormones require precise mcg dosing
- •Small changes can have significant health effects
- •Laboratory analysis often measures mcg levels
Medical Importance
Microgram-level precision is crucial for medications with narrow therapeutic windows, where small dose changes can mean the difference between therapeutic effect and toxicity.
Common Conversion Errors
Dangerous Mistake: Confusing mcg with mg
• 250 mcg ≠ 250 mg
• 250 mcg = 0.25 mg (1000× smaller!)
• Always verify decimal placement
Remember: mcg is much smaller than mg
Step-by-Step Medical Examples
Example 1: Thyroid Medication
Problem: Convert 125 mcg levothyroxine to mg
Step 1: Use the formula: mg = mcg ÷ 1000
Step 2: mg = 125 ÷ 1000
Step 3: mg = 0.125
Answer: 125 mcg = 0.125 mg
Check: 0.125 mg × 1000 = 125 mcg ✓
Example 2: Vitamin B12
Problem: Convert 0.5 mg vitamin B12 to mcg
Step 1: Use the formula: mcg = mg × 1000
Step 2: mcg = 0.5 × 1000
Step 3: mcg = 500
Answer: 0.5 mg = 500 mcg
Check: 500 mcg ÷ 1000 = 0.5 mg ✓