Convert kilograms to milligrams

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Type a value in kilograms and read the result in milligrams. One kilogram is a million milligrams, so 4 kg gives 4,000,000 mg. The result appears as you type, and the page also has a table of masses from packaging and scales, with the same result in scientific notation.

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How many milligrams is a given number of kilograms?

Multiply the number of kilograms by a million and you have the value in milligrams. Four kilograms come to 4,000,000 mg.


Formula: milligrams = kilograms × 1,000,000


The multiplier is round because it is built from two steps of a thousand: a kilogram splits into a thousand grams, and a gram into a thousand milligrams[1].


In your head, add six zeros or move the decimal point six places to the right. Half a kilogram is 500,000 mg. A quarter of a kilogram is 250,000 mg. A hundredth of a kilogram, 0.01 kg, gives 10,000 mg.


Direction matters here, because the answer grows by six orders of magnitude. A body mass of 70 kg written in milligrams is 70,000,000 mg, a figure that reads more easily in scientific notation, and the conversion table has that column.


Below a kilogram the very same multiplier applies. A 0.05 kg weight is 50,000 mg and a 0.001 kg sample is exactly one gram.


For the opposite direction, use the milligrams to kilograms converter.

What is a kilogram and what is a milligram?

The kilogram is the SI base unit of mass, and since 2019 its value has been based on a fixed numerical value of the Planck constant, 6.626 070 15 × 10⁻³⁴ expressed in the unit joule second[2]. A scale reads the same figure after that change as before it; what is new is only the way the standard is realised.


The gram is one thousandth of a kilogram[3], and it is the gram that takes the prefixes, because the name of the base unit already carries kilo. That is where the milligram comes from: the prefix milli means one thousandth[1], so a milligram is a thousandth of a gram and a millionth of a kilogram at the same time.


Both units measure the same physical quantity on a different scale. Kilograms are used for shopping and body mass; milligrams for a dose, a nutrient on a label and a laboratory sample. A laboratory balance reads masses in the milligram range.


The microgram, a millionth of a gram, is a thousand times smaller than the milligram, and the tonne is a thousand times larger than the kilogram. To convert kilograms to grams, use the separate converter.

How many milligrams are 0.5 kg, 1 kg and 5 kg?

The table gathers masses that really do appear on a scale and on packaging: from a single gram, through food and equipment masses, up to body mass and a full tonne. The scientific notation column shortens the long figures, and the grams column shows the value halfway through this conversion.
KilogramsMilligramsScientific notationGrams
0.001 kg1,000 mg1 × 10³ mg1 g
0.005 kg5,000 mg5 × 10³ mg5 g
0.01 kg10,000 mg1 × 10⁴ mg10 g
0.025 kg25,000 mg2.5 × 10⁴ mg25 g
0.04 kg40,000 mg4 × 10⁴ mg40 g
0.05 kg50,000 mg5 × 10⁴ mg50 g
0.1 kg100,000 mg1 × 10⁵ mg100 g
0.2 kg200,000 mg2 × 10⁵ mg200 g
0.25 kg250,000 mg2.5 × 10⁵ mg250 g
0.4 kg400,000 mg4 × 10⁵ mg400 g
0.5 kg500,000 mg5 × 10⁵ mg500 g
0.55 kg550,000 mg5.5 × 10⁵ mg550 g
0.75 kg750,000 mg7.5 × 10⁵ mg750 g
0.98 kg980,000 mg9.8 × 10⁵ mg980 g
1 kg1,000,000 mg1 × 10⁶ mg1,000 g
1.2 kg1,200,000 mg1.2 × 10⁶ mg1,200 g
1.5 kg1,500,000 mg1.5 × 10⁶ mg1,500 g
2 kg2,000,000 mg2 × 10⁶ mg2,000 g
2.25 kg2,250,000 mg2.25 × 10⁶ mg2,250 g
2.5 kg2,500,000 mg2.5 × 10⁶ mg2,500 g
2.77 kg2,770,000 mg2.77 × 10⁶ mg2,770 g
3 kg3,000,000 mg3 × 10⁶ mg3,000 g
3.1 kg3,100,000 mg3.1 × 10⁶ mg3,100 g
3.5 kg3,500,000 mg3.5 × 10⁶ mg3,500 g
3.92 kg3,920,000 mg3.92 × 10⁶ mg3,920 g
4 kg4,000,000 mg4 × 10⁶ mg4,000 g
4.5 kg4,500,000 mg4.5 × 10⁶ mg4,500 g
5 kg5,000,000 mg5 × 10⁶ mg5,000 g
5.2 kg5,200,000 mg5.2 × 10⁶ mg5,200 g
5.6 kg5,600,000 mg5.6 × 10⁶ mg5,600 g
6 kg6,000,000 mg6 × 10⁶ mg6,000 g
7 kg7,000,000 mg7 × 10⁶ mg7,000 g
8 kg8,000,000 mg8 × 10⁶ mg8,000 g
10 kg10,000,000 mg1 × 10⁷ mg10,000 g
15 kg15,000,000 mg1.5 × 10⁷ mg15,000 g
20 kg20,000,000 mg2 × 10⁷ mg20,000 g
25 kg25,000,000 mg2.5 × 10⁷ mg25,000 g
30 kg30,000,000 mg3 × 10⁷ mg30,000 g
34 kg34,000,000 mg3.4 × 10⁷ mg34,000 g
38 kg38,000,000 mg3.8 × 10⁷ mg38,000 g
50 kg50,000,000 mg5 × 10⁷ mg50,000 g
60 kg60,000,000 mg6 × 10⁷ mg60,000 g
70 kg70,000,000 mg7 × 10⁷ mg70,000 g
75 kg75,000,000 mg7.5 × 10⁷ mg75,000 g
100 kg100,000,000 mg1 × 10⁸ mg100,000 g
500 kg500,000,000 mg5 × 10⁸ mg500,000 g
1,000 kg1,000,000,000 mg1 × 10⁹ mg1,000,000 g
Values in the milligrams column grow quickly, because every kilogram is a million milligrams. To convert the value in grams to milligrams, use the grams to milligrams converter.

How much substance does a limit in mg/kg allow in a given mass?

Written as mg/kg, the notation gives a content: the number of milligrams of a substance per kilogram of material. The table turns such a limit into four masses you actually work with: a 100 g portion, a kilogram, a 25 kg sack and a tonne. The EPA states the same kind of limit in parts per million, defining a tolerance as the maximum residue level of a pesticide, usually measured in ppm[4].
LimitIn 100 gIn 1 kgIn a 25 kg sackIn a tonne
0.01 mg/kg0.001 mg0.01 mg0.25 mg10 mg
0.02 mg/kg0.002 mg0.02 mg0.5 mg20 mg
0.05 mg/kg0.005 mg0.05 mg1.25 mg50 mg
0.1 mg/kg0.01 mg0.1 mg2.5 mg100 mg
0.2 mg/kg0.02 mg0.2 mg5 mg200 mg
0.5 mg/kg0.05 mg0.5 mg12.5 mg500 mg
1 mg/kg0.1 mg1 mg25 mg1,000 mg
2 mg/kg0.2 mg2 mg50 mg2,000 mg
5 mg/kg0.5 mg5 mg125 mg5,000 mg
10 mg/kg1 mg10 mg250 mg10,000 mg
20 mg/kg2 mg20 mg500 mg20,000 mg
50 mg/kg5 mg50 mg1,250 mg50,000 mg
The figure beside mg/kg stays the same whatever the sample weighs, because it describes a ratio of two masses. What grows is the amount in the whole batch: at a limit of 0.05 mg/kg, a tonne of material holds 50 mg.

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
2.52500000 mgThe decimal point from the numeric keypad, written the way English writes it
2,52500000 mgA comma pasted from a market that writes decimals that way is read as a decimal point, so the result is the same
1,5001500000000 mgThree 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 mgWe work the fraction out ourselves, so there is no need to turn it into a decimal first
3½3500000 mgThe ½ character copied from a recipe or a label is added to the number in front of it
2.5 kg2500000 mgA unit symbol pasted along with the number is no trouble: we take the number and leave the symbol out

How do you convert kilograms to milligrams in a spreadsheet?

The arithmetic comes down to a single multiplication, and Excel also has a built-in function with a list of units. These steps cover both, along with the way large numbers are written.

  1. Type the number of kilograms into a cell

    Say it is in cell A1. There may be more values — put them one under another so the formula from the next step can be dragged down the column.

  2. Multiply that cell by a million

    In the next cell type =A1*1000000. For 4 kg the sheet shows 4000000, and for 0.25 kg it shows 250000.

  3. Or use the CONVERT function

    Its syntax is CONVERT(number, from_unit, to_unit)[5]. The gram is coded as "g", kilo as "k" and milli as "m", so the conversion reads =CONVERT(A1,"kg","mg").

  4. Keep large numbers readable

    Seventy kilograms give 70,000,000 mg, so the column grows wide fast. A cell format with a thousands separator splits the figure every three digits, and scientific format shortens it to 7E+07.

When is a mass given in milligrams rather than kilograms?

The order of magnitude decides, and the aim is a figure that reads without a run of zeros. Vitamin C listed as 80 mg would appear in kilograms as 0.00008 kg, so the label stays with milligrams. A 25 kg sack of cement written in milligrams is 25,000,000 mg, eight digits, so the packaging stays with kilograms.


The same rule applies in the laboratory and in industry. A sample for analysis is weighed out in milligrams, because that is the range a laboratory balance reads, while a delivery of raw material is counted in kilograms or tonnes.


Between the two is the gram, and that is the unit for masses in the middle: a portion of a product, a weighed-out sample, the contents of a pack. For values in grams, use the grams to kilograms converter.

A shop balance with a dial marked GRAMMES and two brass pans
The dial of this balance is marked in grams from 0 to 25, and the words PORTEE MAXIMUM 2 KILOG. give its maximum capacity of 2 kg. A gram and a kilogram are a thousand apart, while a kilogram and a milligram are a million apart. Photo: Piret Ilver, Unsplash.

Convert other units to Milligrams

g to mgmcg to mgoz to mg

Convert Kilograms to other units

kg to lbkg to gkg to dgkg to mcgkilograms to ounceskg to stonekilograms to tons

Sources

  1. Metric (SI) Prefixes — National Institute of Standards and Technology
  2. SI base unit: kilogram (kg) — International Bureau of Weights and Measures (BIPM)
  3. Gram — Wikipedia
  4. Pesticide Registration Manual: Chapter 11 — Tolerance Petitions — United States Environmental Protection Agency
  5. CONVERT function — Microsoft

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 kilograms to milligrams

How many milligrams are in 1 kg?

1,000,000 mg. A kilogram splits into a thousand grams and each gram into a thousand milligrams, which makes a million together. Milligrams back into grams go through the mg to g converter.

How many milligrams are in half a kilogram?

500,000 mg. A quarter of a kilogram is 250,000 mg, and 0.1 kg is 100,000 mg.

How do you convert kg to mg in your head?

Add six zeros, or move the decimal point six places to the right. 2 kg becomes 2,000,000 mg and 0.75 kg becomes 750,000 mg.

How many milligrams is a body mass of 70 kg?

70,000,000 mg, or 7 × 10⁷ mg. In practice body mass stays in kilograms, because doses are given in milligrams per kilogram of that mass.

What is the difference between kg and mg in writing?

The prefix. The symbol kg means kilogram, a thousand grams, while mg means milligram, a thousandth of a gram. A million separates them. Both prefixes are written in lower case and attach to the same letter g; capital M is a different prefix, mega, meaning a million.

Will the field take a decimal?

Yes. The field accepts a point or a comma as the decimal mark, and a common fraction such as 1/2 or 2 1/4. The result appears as you type.

How do you write a large number of milligrams in scientific notation?

One kilogram is 1 × 10⁶ mg, ten kilograms is 1 × 10⁷ mg and a hundred kilograms is 1 × 10⁸ mg. The conversion table has a column with that notation.

Arteon free tool screenshot: Convert kilograms to milligrams

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