Astronomical Distance Converter: Convert Space Units
This astronomical distance converter changes a value between units used in astronomy, including meters, kilometers, astronomical units, light-years, parsecs, Earth radii, the mean Moon distance, solar radii, and the Planck length. Enter a value, choose its source and target units, and read the converted figure. Reference values follow IAU definitions and nominal values, plus the CODATA 2018 Planck length.
The Astronomical Distance Converter helps you convert astronomical distances between units such as meters, kilometers, astronomical units, light-years, parsecs, Earth radii, the mean Moon distance, solar radii, and the Planck length. Enter a value, select its source and target units, and use the converted figure in your work.
The conversion values use stated scientific references: the astronomical unit is exactly 149,597,870,700 m by IAU definition, and the light-year is the Julian year multiplied by the speed of light, or 9,460,730,472,580,800 m. The parsec is exact by the IAU 2015 definition (AU / tan 1″). Solar and Earth radii and the mean Moon distance use IAU 2015 nominal values; the Planck length uses the CODATA 2018 value.
Astronomical distances can be expressed on very different scales. Meters and kilometers are familiar metric units, while astronomical units, light-years, and parsecs are used to describe distances in space. Converting between them helps you compare measurements, check calculations, or present a result in a unit that suits your readers. Choose the source and target units to get the representation you need.
The converter runs in your browser, and your input is processed on your device rather than sent to a server. It works offline once the page has loaded, so you can convert values without an active connection. This browser-based tool is useful for developers, DevOps engineers, students, and anyone working with astronomical measurements.
Step 1: Enter the astronomical distance you want to convert. Use the value from your measurement or calculation as the starting point.
Step 2: Choose the source unit for the value. The converter includes astronomical distance units such as meters, kilometers, astronomical units, light-years, and parsecs.
Step 3: Choose the target unit you want to use. Select a unit that fits your calculation, report, or audience.
Step 4: Read the converted figure. For another representation, choose a different source or target unit and convert again.
Use case: Convert an astronomical measurement when your source and target units differ. This makes it easier to compare values expressed in different distance units.
Use case: Check a figure in the unit your audience uses. For example, present a distance in light-years or astronomical units instead of meters.
Use case: Convert a set of values at once instead of rounding each one by hand. This can help when preparing several measurements for a report or calculation.
Use case: Compare a distance with familiar astronomical scales. Converting between units such as kilometers, Earth radii, and the mean Moon distance can make a value easier to interpret.
Use case: Work with scientific values that use parsecs or light-years. Convert them to another supported unit when a calculation or document calls for a different representation.
Use case: Review a value based on a defined astronomical reference. The converter uses stated IAU definitions and nominal values, as well as the CODATA 2018 Planck length.