Convert Terameter to Petameter
Convert terameters to petameters instantly. 1 terameter = 0.001 petameter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Petameter to Terameter converter for the reverse conversion.
Units explained
Terameter
A terameter is a metric unit of length equal to one trillion meters (1×10¹² m). It is rare in everyday use but appears in astronomy when expressing solar-system-scale distances in SI units.
The terameter uses the SI prefix tera- (from Greek teras, monster), adopted by the CGPM in 1960 to denote multiplication by one trillion (10¹²).
Terameters are occasionally used in astronomy to express distances on the order of Earth–Sun (~0.15 Tm or 1 AU) and outer-planet distances. The astronomical unit (AU) and light-hour are more common in practice.
SI prefix tera- adopted in 1960; the terameter is the standard SI prefix unit for distances comparable to inter-planetary scales but is less common than the AU in working astronomy.
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.
Terameter to Petameter conversion formula
The relationship between terameters and petameters:
To convert terameters to petameters, multiply the value in terameters by 0.001. To reverse, multiply petameters by 1000.
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 Terameter converter for the reverse direction.
Step-by-step: convert terameters to petameters
- Write down the value in terameters (Tm).
- Multiply that value by the factor 0.001.
- The product is the equivalent value in petameters (Pm).
- To reverse, multiply the petameter value by 1000.
Worked examples
Example 1 — Convert 1 Tm to Pm:
1 × 0.001 = 0.001 Pm
Example 2 — Convert 100 Tm to Pm:
100 × 0.001 = 0.1 Pm
Terameter to Petameter conversion table
Standard reference values for converting terameters to petameters:
| Terameter [Tm] | Petameter [Pm] |
|---|---|
| 0.01 | 1e-5 |
| 0.1 | 0.0001 |
| 1 | 0.001 |
| 2 | 0.002 |
| 3 | 0.003 |
| 4 | 0.004 |
| 5 | 0.005 |
| 10 | 0.01 |
| 20 | 0.02 |
| 30 | 0.03 |
| 40 | 0.04 |
| 50 | 0.05 |
| 100 | 0.1 |
| 500 | 0.5 |
| 1000 | 1 |
Frequently asked questions
How many petameters is 1 terameter?
How do I convert terameters to petameters?
How do I convert petameters back to terameters?
How many petameters is 100 terameters?
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Sources & references
Conversion factor (1 Tm = 0.001 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 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.