Convert Gigameter to Exameter
Convert gigameters to exameters instantly. 1 gigameter = 1e-9 exameter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Exameter to Gigameter converter for the reverse conversion.
Units explained
Gigameter
A gigameter is a metric unit of length equal to one billion meters (1×10⁹ m). It is most often used in astronomy and astrophysics when expressing distances within the inner solar system.
The gigameter uses the SI prefix giga- (from Greek gigas, giant), adopted by the CGPM in 1960 to denote multiplication by one billion (10⁹).
Gigameters are used to express distances such as the Sun's diameter (~1.39 Gm), the Earth–Moon distance (~0.384 Gm), and similar inner-solar-system scales. Astronomical units and light-seconds are also common for these distances.
SI prefix giga- adopted in 1960; the gigameter became standard in astronomy for sub-AU distances by the late 20th century.
Exameter
An exameter is a metric unit of length equal to one quintillion meters (1×10¹⁸ m). It is among the largest defined SI prefix units of length and appears almost exclusively in astrophysical contexts.
The exameter uses the SI prefix exa- (from Greek hex, six, related to the exponent's powers-of-thousand grouping), adopted by the CGPM in 1975 to denote 10¹⁸.
Exameters could be used to express galactic-scale distances. One kiloparsec is approximately 30.9 Em. Astronomy generally uses parsecs, kiloparsecs, and megaparsecs instead.
SI prefix exa- adopted in 1975; the exameter has very limited practical use because galactic-scale astronomy has its own well-established unit system.
Gigameter to Exameter conversion formula
The relationship between gigameters and exameters:
To convert gigameters to exameters, multiply the value in gigameters by 1e-9. To reverse, multiply exameters by 1e+9.
How to use this converter
Type a value into the calculator. The result in exameters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Exameter to Gigameter converter for the reverse direction.
Step-by-step: convert gigameters to exameters
- Write down the value in gigameters (Gm).
- Multiply that value by the factor 1e-9.
- The product is the equivalent value in exameters (Em).
- To reverse, multiply the exameter value by 1e+9.
Worked examples
Example 1 — Convert 1 Gm to Em:
1 × 1e-9 = 1e-9 Em
Example 2 — Convert 100 Gm to Em:
100 × 1e-9 = 1e-7 Em
Gigameter to Exameter conversion table
Standard reference values for converting gigameters to exameters:
| Gigameter [Gm] | Exameter [Em] |
|---|---|
| 0.01 | 1e-11 |
| 0.1 | 1e-10 |
| 1 | 1e-9 |
| 2 | 2e-9 |
| 3 | 3e-9 |
| 4 | 4e-9 |
| 5 | 5e-9 |
| 10 | 1e-8 |
| 20 | 2e-8 |
| 30 | 3e-8 |
| 40 | 4e-8 |
| 50 | 5e-8 |
| 100 | 1e-7 |
| 500 | 5e-7 |
| 1000 | 1e-6 |
Frequently asked questions
How many exameters is 1 gigameter?
How do I convert gigameters to exameters?
How do I convert exameters back to gigameters?
How many exameters is 100 gigameters?
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Sources & references
Conversion factor (1 Gm = 1e-9 Em) 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 Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.