How many micrograms are in one gram?

There are exactly 1,000,000 micrograms (µg or mcg) in one gram (g). This is because the prefix "micro-" means one millionth (10⁻⁶), so 1 g = 10⁶ µg.

What is the symbol for microgram?

The SI symbol is µg (micro + gram). In medical and nutrition contexts it is also written as "mcg" to avoid confusion between the Greek letter µ and the letter u in handwriting.

Can I convert decimal gram values?

Yes. The converter accepts any positive number including decimals such as 0.001 g or 2.5 g. Just type the value and the result updates instantly.

How do I convert micrograms back to grams?

Divide the microgram value by 1,000,000, or use the swap button in this tool to switch the direction of the conversion automatically.

Is this converter accurate for scientific use?

Yes. The conversion factor is exact (defined by SI). Results are displayed with up to 10 significant digits to minimize rounding error for small values.

Grams to Micrograms Converter

Enter a value in grams and instantly get the equivalent in micrograms (1 g = 1,000,000 mcg).

Enter Value

Grams (g)

Micrograms (mcg / µg)

Result

Micrograms (µg)

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Grams (g)

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Conversion factor: 1 g = 1,000,000 µg (exact, SI definition)

Common Gram to Microgram Conversions

Grams (g)	Micrograms (µg)

Summary

This tool converts a mass expressed in grams (g) to micrograms (mcg or µg) using the exact factor of 1,000,000. Micrograms are commonly used in pharmacology, nutrition labeling, and scientific research where very small masses must be expressed precisely. Enter any gram value — including decimals — and the equivalent microgram result appears instantly.

How it works

Type a mass value in the grams input field.
The converter multiplies the value by 1,000,000 (the exact g-to-mcg factor).
The result in micrograms appears immediately below.
Click "Copy Result" to copy the microgram value to your clipboard.
Use the swap button to reverse the conversion (micrograms to grams).

Use cases

Convert medication dosages from grams to micrograms for pharmacy calculations.
Check dietary supplement amounts on nutrition labels (e.g. vitamin D in mcg).
Perform unit conversions in chemistry or biology lab work.
Verify analytical chemistry measurements expressed in µg.
Convert scientific data between SI mass units for research papers.
Quickly cross-check microgram quantities when preparing solutions.

Frequently Asked Questions

Last updated: 2026-10-05 · Reviewed by Nham Vu