mcg to IU Converter
Convert micrograms to International Units for vitamins and hormones with substance-specific accuracy.
For informational purposes only. IU values vary by substance - always check product labels for accurate measurements.
Vitamin Converter
Conversion Results
Enter amount and select substance to calculate IU
mcg to IU Conversion
Converting micrograms to International Units is essential for understanding vitamin and hormone dosages. While micrograms measure weight, International Units measure biological activity. The key is that different substances have different conversion factors - there's no universal formula that works for everything.
The Conversion Formula
The calculator divides the weight in micrograms by the substance's specific conversion factor:
For example, converting 50 mcg of vitamin D:
Common Vitamin Conversion Factors
| Vitamin/Hormone | mcg per 1 IU | Example |
|---|---|---|
| Vitamin A (Retinol) | 0.3 mcg | 900 mcg = 3000 IU |
| Vitamin A (Beta-Carotene) | 0.6 mcg | 600 mcg = 1000 IU |
| Vitamin D | 0.025 mcg | 50 mcg = 2000 IU |
| Vitamin D2 (Ergocalciferol) | 0.025 mcg | 25 mcg = 1000 IU |
| Vitamin D3 (Cholecalciferol) | 0.025 mcg | 25 mcg = 1000 IU |
| Vitamin E (Natural) | 0.67 mcg | 15 mcg = 22.4 IU |
| Vitamin E (Synthetic) | 0.45 mcg | 15 mcg = 33.3 IU |
| Vitamin K1 (Phylloquinone) | 0.056 mcg | 56 mcg = 1000 IU |
| Vitamin K2 (Menaquinone) | 0.056 mcg | 56 mcg = 1000 IU |
| Insulin (Human) | 0.0347 mcg | 34.7 mcg = 1000 IU |
| Insulin (Animal) | 0.0347 mcg | 34.7 mcg = 1000 IU |
| Vitamin B12 (Cyanocobalamin) | 0.136 mcg | 136 mcg = 1000 IU |
| Vitamin C (Ascorbic Acid) | 50 mcg | 50 mg = 1000 IU |
| Folic Acid | 0.5 mcg | 500 mcg = 1000 IU |
| Vitamin B1 (Thiamine) | 3 mcg | 3 mg = 1000 IU |
Practical Applications
This converter is invaluable for anyone reading supplement labels or managing nutritional intake. When a vitamin D supplement lists 2000 IU, you can use this calculator to understand what that means in micrograms. Healthcare providers and nutritionists use these conversions for treatment planning and dietary counseling.
The calculator includes scientifically established conversion factors from authoritative sources. For unusual substances, you can enter a custom conversion factor. Always verify conversion factors from reliable scientific references for critical applications.
Remember, while International Units provide standardization across different forms of vitamins, actual nutritional needs vary by individual factors like age, health status, and lifestyle. This calculator provides mathematical conversions but should not replace professional nutritional advice.