Convert Milligram to Attogram
Convert milligrams to attograms instantly. 1 milligram = 1e+15 attogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Attogram to Milligram converter for the reverse conversion.
Units explained
Milligram
A milligram (mg) equals one-millionth of a kilogram, or 0.001 gram.
From the SI prefix 'milli-' (from Latin 'mille', thousand).
Standard for medicine dosing, nutrition labels, and fine jewelry.
Part of the original metric system of 1795.
Attogram
An attogram (ag) equals 10^-21 kilogram.
From the SI prefix 'atto-' (from Danish 'atten', eighteen).
Frontier nanoscience and single-molecule mass detection.
The atto- prefix was adopted by the CGPM in 1975.
Milligram to Attogram conversion formula
The relationship between milligrams and attograms:
To convert milligrams to attograms, multiply the value in milligrams by 1e+15. To reverse, multiply attograms by 1e-15.
How to use this converter
Type a value into the calculator. The result in attograms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Attogram to Milligram converter for the reverse direction.
Step-by-step: convert milligrams to attograms
- Write down the value in milligrams (mg).
- Multiply that value by the factor 1e+15.
- The product is the equivalent value in attograms (ag).
- To reverse, multiply the attogram value by 1e-15.
Worked examples
Example 1 — Convert 1 mg to ag:
1 × 1e+15 = 1e+15 ag
Example 2 — Convert 100 mg to ag:
100 × 1e+15 = 1e+17 ag
Real-world example — Mid-micron to nanometer
3 milligrams equals 3,000 attograms — useful when relating mid-infrared wavelengths (typically quoted in microns) to nanometer-scale visible-light wavelength tables.
3 mg × 1e+15 = 3e+15 ag
Real-world example — From microns to sub-micron features
One milligram equals one thousand attograms — the conversion semiconductor designers do constantly when comparing mask feature dimensions to actual transistor gate lengths.
1 mg × 1e+15 = 1e+15 ag
Real-world example — Infrared to visible-spectrum mapping
A 10-milligram thermal infrared wavelength corresponds to a much larger number in attograms, the unit favoured for ultraviolet and visible-light specifications.
10 mg × 1e+15 = 1e+16 ag
Milligram to Attogram conversion table
Standard reference values for converting milligrams to attograms:
| Milligram [mg] | Attogram [ag] |
|---|---|
| 0.01 | 1e+13 |
| 0.1 | 1e+14 |
| 1 | 1e+15 |
| 2 | 2e+15 |
| 3 | 3e+15 |
| 4 | 4e+15 |
| 5 | 5e+15 |
| 10 | 1e+16 |
| 20 | 2e+16 |
| 30 | 3e+16 |
| 40 | 4e+16 |
| 50 | 5e+16 |
| 100 | 1e+17 |
| 500 | 5e+17 |
| 1000 | 1e+18 |
Frequently asked questions
How many attograms is 1 milligram?
How do I convert milligrams to attograms?
How do I convert attograms back to milligrams?
How many attograms is 100 milligrams?
Popular weight unit conversions
Convert Milligram to other weight units
Show all Milligram conversions
Metric / SI (17 units)
Avoirdupois (15 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Sources & references
Conversion factor (1 mg = 1e+15 ag) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.