Length · Unit Converter

Convert Attometer to Petameter

Convert attometers to petameters instantly. 1 attometer = 1e-33 petameter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Petameter to Attometer converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Length category 2 min read Published Last reviewed Updated

Units explained

Metric / SI

Attometer

What is a attometer?

An attometer is a metric unit of length equal to one quintillionth of a meter (1×10⁻¹⁸ m). It is among the smallest length units in the SI system and is used almost exclusively in particle physics and theoretical work involving sub-nuclear dimensions.

Origin of the attometer

The attometer was defined using the SI prefix atto- (from Danish atten, meaning eighteen), adopted by the Conférence Générale des Poids et Mesures (CGPM) in 1964 to denote one quintillionth (10⁻¹⁸).

Where it is used

Attometers appear in particle physics literature when describing distances comparable to or smaller than nuclear dimensions, including the range of weak nuclear interactions and theoretical Planck-scale ratios. They are rarely encountered outside specialised scientific work.

When and where it was developed

SI prefix atto- adopted in 1964; the attometer became the standard unit for sub-femtometer measurements in high-energy physics from the late 20th century onward.

Metric / SI

Petameter

What is a 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.

Origin of the petameter

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.

Where it is used

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.

When and where it was developed

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.

Attometer to Petameter conversion formula

The relationship between attometers and petameters:

1 am = 1e-33 Pm
1 Pm = 1e+33 am

To convert attometers to petameters, multiply the value in attometers by 1e-33. To reverse, multiply petameters by 1e+33.

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 Attometer converter for the reverse direction.

Step-by-step: convert attometers to petameters

  1. Write down the value in attometers (am).
  2. Multiply that value by the factor 1e-33.
  3. The product is the equivalent value in petameters (Pm).
  4. To reverse, multiply the petameter value by 1e+33.

Worked examples

Example 1 — Convert 1 am to Pm:
1 × 1e-33 = 1e-33 Pm

Example 2 — Convert 100 am to Pm:
100 × 1e-33 = 1e-31 Pm

Real-world example — Molecular dimensions

The diameter of small molecular structures (around 2 attometers) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.

2 am × 1e-33 = 2e-33 Pm

Real-world example — Wavelengths across the spectrum

Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 attometers can be re-expressed in petameters for direct comparison with another instrument's calibration data sheet.

800 am × 1e-33 = 8e-31 Pm

Attometer to Petameter conversion table

Standard reference values for converting attometers to petameters:

Attometer [am]Petameter [Pm]
0.011e-35
0.11e-34
11e-33
22e-33
33e-33
44e-33
55e-33
101e-32
202e-32
303e-32
404e-32
505e-32
1001e-31
5005e-31
10001e-30

Frequently asked questions

How many petameters is 1 attometer?
1 attometer equals 1e-33 petameter.
How do I convert attometers to petameters?
Multiply the value in attometers by 1e-33 to get petameters.
How do I convert petameters back to attometers?
Multiply the value in petameters by 1e+33, or use the Petameter to Attometer converter.
How many petameters is 100 attometers?
100 attometers equals 1e-31 petameters, because 100 × 1e-33 = 1e-31.

Convert Attometer to other length units

Show all Attometer conversions

Sources & references

Conversion factor (1 am = 1e-33 Pm) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.