Convert Microgram to Milligram
1 microgram = 0.001 milligram (mg). For example, 10 microgram = 0.01 milligram and 100 microgram = 0.1 milligram. Type any value below to convert microgram to milligram both ways — it runs entirely in your browser.
Quick answer: Microgram to Milligram
1 Microgram = 0.001 Milligram (µg → mg). To convert microgram to milligram, multiply by 0.001. To convert milligram to microgram, multiply by 1,000. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common microgram-to-milligram questions.
How to convert Microgram to Milligram
To convert microgram to milligram, multiply the number of microgram by the conversion factor 0.001, because 1 µg = 0.001 mg. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 mg = 1,000 µg, so you divide by 0.001 (or multiply by 1,000) to turn milligram back into microgram.
mg = µg × 0.001 ·
µg = mg × 1,000
- Write down the value you want to convert, in microgram.
- Multiply it by 0.001.
- The result is the same area/length/quantity expressed in milligram.
Microgram to Milligram — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 microgram is 0.005 milligram because 5 µg × 0.001 = 0.005 mg.
| Microgram | Calculation | Milligram |
|---|---|---|
| 1 µg | 1 µg × 0.001 = 0.001 mg | 0.001 mg |
| 2 µg | 2 µg × 0.001 = 0.002 mg | 0.002 mg |
| 3 µg | 3 µg × 0.001 = 0.003 mg | 0.003 mg |
| 5 µg | 5 µg × 0.001 = 0.005 mg | 0.005 mg |
| 7 µg | 7 µg × 0.001 = 0.007 mg | 0.007 mg |
| 10 µg | 10 µg × 0.001 = 0.01 mg | 0.01 mg |
| 12 µg | 12 µg × 0.001 = 0.012 mg | 0.012 mg |
| 15 µg | 15 µg × 0.001 = 0.015 mg | 0.015 mg |
| 20 µg | 20 µg × 0.001 = 0.02 mg | 0.02 mg |
| 25 µg | 25 µg × 0.001 = 0.025 mg | 0.025 mg |
| 50 µg | 50 µg × 0.001 = 0.05 mg | 0.05 mg |
| 100 µg | 100 µg × 0.001 = 0.1 mg | 0.1 mg |
Common Microgram to Milligram conversions
These are the microgram-to-milligram values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 microgram = 0.001 milligram
- 2 microgram = 0.002 milligram
- 2.5 microgram = 0.0025 milligram
- 3 microgram = 0.003 milligram
- 4 microgram = 0.004 milligram
- 5 microgram = 0.005 milligram
- 6 microgram = 0.006 milligram
- 7 microgram = 0.007 milligram
- 8 microgram = 0.008 milligram
- 9 microgram = 0.009 milligram
- 10 microgram = 0.01 milligram
- 12 microgram = 0.012 milligram
- 15 microgram = 0.015 milligram
- 20 microgram = 0.02 milligram
- 25 microgram = 0.025 milligram
- 30 microgram = 0.03 milligram
- 50 microgram = 0.05 milligram
- 75 microgram = 0.075 milligram
- 100 microgram = 0.1 milligram
- 200 microgram = 0.2 milligram
- 500 microgram = 0.5 milligram
- 1000 microgram = 1 milligram
Microgram to Milligram conversion chart (both directions)
The chart below converts microgram to milligram and milligram to microgram side by side, so it works whichever way you need. 1 microgram = 0.001 milligram, and 1 milligram = 1,000 microgram.
| Microgram → Milligram | Milligram → Microgram |
|---|---|
| 0.25 µg = 0.00025 mg | 0.25 mg = 250 µg |
| 0.5 µg = 0.0005 mg | 0.5 mg = 500 µg |
| 1 µg = 0.001 mg | 1 mg = 1,000 µg |
| 2 µg = 0.002 mg | 2 mg = 2,000 µg |
| 3 µg = 0.003 mg | 3 mg = 3,000 µg |
| 4 µg = 0.004 mg | 4 mg = 4,000 µg |
| 5 µg = 0.005 mg | 5 mg = 5,000 µg |
| 6 µg = 0.006 mg | 6 mg = 6,000 µg |
| 7 µg = 0.007 mg | 7 mg = 7,000 µg |
| 8 µg = 0.008 mg | 8 mg = 8,000 µg |
| 9 µg = 0.009 mg | 9 mg = 9,000 µg |
| 10 µg = 0.01 mg | 10 mg = 10,000 µg |
| 12 µg = 0.012 mg | 12 mg = 12,000 µg |
| 15 µg = 0.015 mg | 15 mg = 15,000 µg |
| 20 µg = 0.02 mg | 20 mg = 20,000 µg |
| 25 µg = 0.025 mg | 25 mg = 25,000 µg |
| 30 µg = 0.03 mg | 30 mg = 30,000 µg |
| 40 µg = 0.04 mg | 40 mg = 40,000 µg |
| 50 µg = 0.05 mg | 50 mg = 50,000 µg |
| 75 µg = 0.075 mg | 75 mg = 75,000 µg |
| 100 µg = 0.1 mg | 100 mg = 100,000 µg |
| 150 µg = 0.15 mg | 150 mg = 150,000 µg |
| 200 µg = 0.2 mg | 200 mg = 200,000 µg |
| 250 µg = 0.25 mg | 250 mg = 250,000 µg |
| 500 µg = 0.5 mg | 500 mg = 500,000 µg |
| 1000 µg = 1 mg | 1000 mg = 1,000,000 µg |
Microgram vs Milligram: which is bigger?
A milligram is the larger unit: one milligram equals 1,000 micrograms. Put another way, you need 1,000 micrograms to make a single milligram.
What is a Microgram? History, origin and usage
The microgram is one millionth of a gram, and its correct symbol is µg using the Greek letter mu. In handwriting and on older printers the µ was regularly misread as an "m", which turns a microgram into a milligram — a thousand-fold overdose. Medication-safety bodies responded by asking prescribers to spell it "mcg" instead, and that spelling is now what most labels use.
Micrograms are used for the most potent substances and the smallest quantities: vitamin B12 and vitamin D, thyroid hormone, folic acid, many inhaled medicines, and trace contaminants in air and water testing.
The "mcg" spelling exists purely as a safety measure, not as a separate unit — mcg and µg are the same thing. Vitamin D is a good example of why the unit matters: a typical daily supplement is measured in tens of micrograms, an amount far too small to see.
What is a Milligram? History, origin and usage
The milligram arrived with the metric system itself in the 1790s as simply one thousandth of a gram — no separate standard was ever needed, because the metric prefixes do the work. It became important later, when chemistry and pharmacy started needing to state quantities far too small to write in grams.
Milligrams are the language of medicine and nutrition: tablet strengths, vitamin content, caffeine in a cup of coffee, and the daily limits on sodium or cholesterol are all written in milligrams.
A standard aspirin tablet is 325 milligrams and a grain of table salt is around 0.06 milligrams. Because doses are written this way, a single misplaced decimal point in a milligram figure is one of the classic causes of medication error.
Convert 1 Microgram to other units
It can help to see a microgram next to the other units it is commonly compared with. One microgram (µg) is equal to:
| 1 Microgram equals | Unit |
|---|---|
| 0.000000001 kg | Kilogram |
| 0.000001 g | Gram |
| 0.001 mg | Milligram |
| 0.000000000001 t | Tonne |
| 0.00000000001 q | Quintal |
| 0.000000002204623 lb | Pound |
| 0.00000003527396 oz | Ounce |
| 0.000000000157473 st | Stone |
| 0.000000000001102311 ton (US) | Short ton |
| 0.0000000000009842065 ton (UK) | Long ton |
| 0.00000003215075 oz t | Troy ounce |
| 0.00001543236 gr | Grain |
| 0.000005 ct | Carat |
Convert 1 Milligram to other units
One milligram (mg) is equal to:
| 1 Milligram equals | Unit |
|---|---|
| 0.000001 kg | Kilogram |
| 0.001 g | Gram |
| 1,000 µg | Microgram |
| 0.000000001 t | Tonne |
| 0.00000001 q | Quintal |
| 0.000002204623 lb | Pound |
| 0.00003527396 oz | Ounce |
| 0.000000157473 st | Stone |
| 0.000000001102311 ton (US) | Short ton |
| 0.0000000009842065 ton (UK) | Long ton |
| 0.00003215075 oz t | Troy ounce |
| 0.01543236 gr | Grain |
| 0.005 ct | Carat |
Tips for converting Microgram to Milligram
- To go from microgram to milligram, multiply by 0.001; to go back, divide by 0.001 (or multiply by 1,000).
- For a quick mental estimate, remember that 1 microgram ≈ 0.001 milligram, so 10 microgram ≈ 0.01 milligram.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this Microgram to Milligram converter
Type a number into the Microgram field and the equivalent in Milligram appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Milligram field to convert the other way (milligram to microgram). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 µg = 0.001 mg), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for microgram-to-milligram conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
- NIST — Definitions of the SI base units — the US National Institute of Standards and Technology reference for the SI base units, used here as an independent cross-check on the base-unit definition.
Weight factors here are exact, anchored to the kilogram: the international pound is exactly 0.45359237 kg, a stone is 14 pounds, a short ton is 2,000 pounds and a long ton is 2,240, a grain is 1/7000 of a pound and a metric carat is exactly 200 mg. So the live tool and every number on this page always agree.
Frequently asked questions
- How many milligram are in 1 microgram?
- 1 microgram = 0.001 milligram (mg). To convert any number of microgram to milligram, multiply by 0.001.
- How do I convert microgram to milligram?
- Multiply the number of microgram by 0.001. For example, 10 microgram = 10 × 0.001 = 0.01 milligram, and 25 microgram = 0.025 milligram.
- How many microgram are in 1 milligram?
- 1 milligram = 1,000 microgram. So to convert milligram back to microgram, multiply by 1,000.
- What is the formula to convert microgram to milligram?
- milligram = microgram × 0.001. The reverse formula is microgram = milligram × 1,000.
- How much is 100 microgram in milligram?
- 100 microgram = 0.1 milligram. (And 1000 microgram = 1 milligram.)
- Which is bigger, a microgram or a milligram?
- A milligram is larger: 1 milligram = 1,000 microgram.
- Is this microgram to milligram converter accurate?
- Yes — every value is computed from the exact 0.001 mg per µg factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert milligram to microgram too?
- Yes. The converter works both ways — enter a value in either field. 1 milligram = 1,000 microgram.