Convert grams to micrograms

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Enter a value in grams and read the result in micrograms. One gram is a million micrograms, so 0.5 g gives 500,000 mcg. The result updates as you type, and when it has many digits, a line under the field also shows it in scientific notation, such as 5 × 10⁵ mcg.

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The field also accepts scientific notation, for example 6.5e-7 or 6.5 × 10⁻⁷.

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How many micrograms are in a gram?

A gram has 1,000,000 micrograms. To convert grams to micrograms, multiply the number of grams by one million, so 0.5 g gives 500,000 mcg.


Formula: micrograms = grams × 1,000,000


The million comes from the prefix micro, which in the SI stands for one millionth of a unit[1]. A microgram is therefore 0.000001 gram. The unit in between is the milligram. A gram has 1,000 mg, and each of those milligrams has 1,000 mcg.


In decimal form, you move the decimal point six places to the right. In this way, 0.25 g becomes 250,000 mcg. A value of 0.003 g gives 3,000 mcg. For whole numbers you add six zeros, so 2 g gives 2,000,000 mcg.


The line under the result field shows the same number in scientific notation, for example 5 × 10⁵ mcg for half a gram.


For the opposite direction, use the micrograms to grams converter. The first step on its own, grams to milligrams, is covered by the grams to milligrams converter.

What is a gram, and what is a microgram?

A gram is one thousandth of a kilogram. The name of the kilogram already contains the prefix kilo, so the prefixes for units of mass are attached to the name “gram” and to the symbol g[2].


Under this rule, one millionth of a kilogram is called a milligram, with the symbol mg[2]. One millionth of a gram is a microgram. Its symbol µg combines the letter g with the Greek letter μ, which stands for the prefix micro[1].


In medical information in the United States, the abbreviation mcg is preferred, while prescription writing guidance in the United Kingdom advises writing “microgram” in full[3]. The number stays the same whichever way the unit is written.

A gray plastic scoop of white powder resting on a layer of the same powder
If the scoop holds 5 g of powder, that is 5,000,000 mcg. Photo: HowToGym, Unsplash.

How many micrograms are in 0.5 g and other fractions of a gram?

The table starts at one thousandth of a gram and ends at a kilogram. The first column gives the result in micrograms. The second shows the same mass in milligrams, which is the result after the first multiplication by 1,000.
GramsMicrogramsMilligrams
0.001 g1,000 mcg1 mg
0.002 g2,000 mcg2 mg
0.003 g3,000 mcg3 mg
0.004 g4,000 mcg4 mg
0.005 g5,000 mcg5 mg
0.01 g10,000 mcg10 mg
0.02 g20,000 mcg20 mg
0.025 g25,000 mcg25 mg
0.05 g50,000 mcg50 mg
0.075 g75,000 mcg75 mg
0.1 g100,000 mcg100 mg
0.15 g150,000 mcg150 mg
0.2 g200,000 mcg200 mg
0.25 g250,000 mcg250 mg
0.3 g300,000 mcg300 mg
0.4 g400,000 mcg400 mg
0.5 g500,000 mcg500 mg
0.6 g600,000 mcg600 mg
0.75 g750,000 mcg750 mg
0.8 g800,000 mcg800 mg
1 g1,000,000 mcg1,000 mg
1.2 g1,200,000 mcg1,200 mg
1.25 g1,250,000 mcg1,250 mg
1.5 g1,500,000 mcg1,500 mg
2 g2,000,000 mcg2,000 mg
2.5 g2,500,000 mcg2,500 mg
3 g3,000,000 mcg3,000 mg
3.5 g3,500,000 mcg3,500 mg
4 g4,000,000 mcg4,000 mg
5 g5,000,000 mcg5,000 mg
6 g6,000,000 mcg6,000 mg
7 g7,000,000 mcg7,000 mg
8 g8,000,000 mcg8,000 mg
9 g9,000,000 mcg9,000 mg
10 g10,000,000 mcg10,000 mg
20 g20,000,000 mcg20,000 mg
25 g25,000,000 mcg25,000 mg
40 g40,000,000 mcg40,000 mg
50 g50,000,000 mcg50,000 mg
100 g100,000,000 mcg100,000 mg
250 g250,000,000 mcg250,000 mg
500 g500,000,000 mcg500,000 mg
1,000 g1,000,000,000 mcg1,000,000 mg
The rows in bold are half a gram, one gram and a kilogram written as 1,000 g.

How many micrograms is 0.0001 g on a balance display?

A laboratory balance shows mass in grams with a set number of decimal places. The table converts the value of the last place into micrograms. It shows the smallest mass a given balance displays as a separate digit.
Last digitMicrogramsDecimal places
0.0001 g100 mcg4
0.00001 g10 mcg5
0.000001 g1 mcg6
0.0000001 g0.1 mcg7
An analytical balance weighs with a resolution of 0.1 mg or better[4]. In grams, that is one unit in the fourth decimal place, which equals 100 mcg. A microbalance is an analytical balance with a scale interval, meaning the smallest step of the reading on the display, of 0.001 mg or less[5]. That interval equals one microgram. An ultra-microbalance has an interval of 0.1 mcg or smaller. Its weighing range is usually 2 to 3 grams[5].
An antique laboratory balance with two pans, a perforated beam and a curved scale
Half a gram on the pan is 500,000 mcg, and 1 mg is 1,000 mcg. Photo: Eric Prouzet, Unsplash.

Which number formats does this converter handle?

Paste the number the way you have it: with a comma, with a point, with a space between thousands, as a fraction or next to a unit symbol. The field reads every one of these formats and converts it for you, and the table shows exactly what it does with each. The converter computed the results itself.
What you typeWhat the converter showsHow we read it
1.51500000 mcgThe decimal point from the numeric keypad, written the way English writes it
1,51500000 mcgA comma pasted from a market that writes decimals that way is read as a decimal point, so the result is the same
1,5001500000000 mcgThree digits follow the comma, so we read it as a thousands separator: the field holds one thousand five hundred. A note under the field shows the other possible reading, 1.5.
3/4750000 mcgWe work the fraction out ourselves, so there is no need to turn it into a decimal first
2½2500000 mcgThe ½ character copied from a recipe or a label is added to the number in front of it
1.5 g1500000 mcgA unit symbol pasted along with the number is no trouble: we take the number and leave the symbol out
2.6e-32600 mcgScientific notation, the way a spreadsheet shows very small numbers, is read as it stands

How do you convert grams to micrograms through milligrams?

Multiplying by one million can be split into two multiplications by 1,000. The first gives milligrams and the second gives micrograms. The StatPearls review of weight conversions for clinical use lists the same chain of units, from kilograms down to micrograms[6].

  1. Multiply grams by 1,000

    The result is in milligrams. In this way, 0.25 g gives 250 mg.

  3. Check the exponent in scientific notation

    When you convert grams to micrograms, the exponent goes up by six. A value of 0.25 g is 2.5 × 10⁻¹ g. The result is therefore 2.5 × 10⁵ mcg, because minus one plus six is five.

  4. Write the result with a single prefix

    In the SI, a unit symbol has only one prefix attached[2]. You can write the same mass as 250,000 mcg or as 250 mg.

Convert other units to Micrograms

mg to mcgkg to mcg

Convert Grams to other units

g to lbg to kgg to mgg to grainsg to caratsg to ozgrams to tons

Sources

  1. Metric (SI) Prefixes — National Institute of Standards and Technology
  2. SP 330, Section 3: Decimal multiples and sub-multiples of SI units — National Institute of Standards and Technology
  3. Microgram — Wikipedia
  4. Analytical balance — Wikipedia
  5. Mikrowaage (German Wikipedia) — Wikipedia
  6. Conversion Weights (Ojo A, Patel P, Boehning AP), StatPearls — National Center for Biotechnology Information

Every figure in the tables was computed from the unit definitions and checked arithmetically before publication. Historical values and the names of local units come from the sources listed above.

Content last reviewed: · written and checked by the Arteon team

Common questions about converting grams to micrograms

Is 1 g the same as 1,000 mcg?

One thousand micrograms make one milligram. A gram is a thousand times larger than a milligram, so it has 1,000,000 mcg.

Do you multiply or divide to convert grams to micrograms?

You multiply by one million. A microgram is a million times smaller than a gram, so the same mass written in micrograms is a larger number. To go from micrograms to grams, divide by one million.

How do you enter a very small mass, such as 0.0000005 g?

Type it in full or in scientific notation. The field accepts 5e-7, 5E-07 and 5 × 10⁻⁷, and each of them gives a result of 0.5 mcg.

How many micrograms are in a kilogram?

A kilogram has 1,000,000,000 mcg, which is a billion micrograms. It is made up of 1,000 g. Each of those grams is a million micrograms. To convert kilograms to micrograms, use the kg to mcg converter, and for milligrams the kilograms to milligrams converter.

Arteon free tool screenshot: Convert grams to micrograms

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