Convert Megameter to Petameter
Convert megameters to petameters instantly. 1 megameter = 1e-9 petameter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Petameter to Megameter converter for the reverse conversion.
Units explained
Megameter
A megameter is a metric unit of length equal to one million meters (1×10⁶ m, or 1,000 km). It is occasionally used in geophysics and astronomy when expressing planetary-scale distances in SI units.
The megameter uses the SI prefix mega- (from Greek megas, great), adopted by the CGPM in 1960 to denote multiplication by one million.
Megameters appear in geophysics (Earth's mean radius is 6.371 Mm), planetary science, and large-scale civil engineering planning. The unit is less common than the kilometer for everyday geographic distances.
SI prefix mega- adopted in 1960; the megameter is the standard SI prefix unit for distances comparable to planetary radii.
Petameter
A petameter is a metric unit of length equal to one quadrillion meters (1×10¹⁵ m). It is rarely used in everyday or scientific contexts; astronomers prefer the light-year or parsec for these scales.
The petameter uses the SI prefix peta- (from Greek penta, five, by analogy with the exponent's relation to thousand-cubed-cubed), adopted by the CGPM in 1975 to denote 10¹⁵.
Petameters could express interstellar-scale distances but are almost never used in practice. A light-year is approximately 9.46 Pm; astronomy uses light-years and parsecs as standard.
SI prefix peta- adopted in 1975; the petameter is rarely used because astronomy has well-established non-SI units (light-year, parsec) for this scale.
Megameter to Petameter conversion formula
The relationship between megameters and petameters:
To convert megameters to petameters, multiply the value in megameters by 1e-9. To reverse, multiply petameters by 1e+9.
How to use this converter
Type a value into the calculator. The result in petameters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Petameter to Megameter converter for the reverse direction.
Step-by-step: convert megameters to petameters
- Write down the value in megameters (Mm).
- Multiply that value by the factor 1e-9.
- The product is the equivalent value in petameters (Pm).
- To reverse, multiply the petameter value by 1e+9.
Worked examples
Example 1 — Convert 1 Mm to Pm:
1 × 1e-9 = 1e-9 Pm
Example 2 — Convert 100 Mm to Pm:
100 × 1e-9 = 1e-7 Pm
Megameter to Petameter conversion table
Standard reference values for converting megameters to petameters:
| Megameter [Mm] | Petameter [Pm] |
|---|---|
| 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 petameters is 1 megameter?
How do I convert megameters to petameters?
How do I convert petameters back to megameters?
How many petameters is 100 megameters?
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Sources & references
Conversion factor (1 Mm = 1e-9 Pm) 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.