Astronomical Units ↔ Kilometers Converter

Convert astronomical distances between AU and kilometers

Astronomical Units (AU)

Enter astronomical units to convert to kilometers

Kilometers (km)

Enter kilometers to convert to astronomical units

Conversion Result

1 AU = 149,597,870.7 km

1 AU = 149.6 million km • 92.96 million miles

1.495978707 × 10⁸ km

🌌 Astronomical Units to Kilometers Conversion Details

AU to Kilometers Formula

kilometers = AU × 149,597,870.7

To convert astronomical units to kilometers, multiply AU by approximately 149.6 million.

Kilometers to AU Formula

AU = kilometers ÷ 149,597,870.7

To convert kilometers to astronomical units, divide kilometers by approximately 149.6 million.

What is an Astronomical Unit?

An astronomical unit (AU) is the average distance between Earth and the Sun:

1 AU = 149,597,870.7 km
= 92,955,807.3 miles
≈ 8.317 light-minutes

Common Uses

Measuring solar system distances
Planetary orbit calculations
Spacecraft navigation
Astronomy education

📏 How This Converter Works

This is a bidirectional converter for astronomical distances:

AU → Kilometers: When you type in the AU field, the km field automatically updates
Kilometers → AU: When you type in the km field, the AU field automatically updates
No swapping needed: Both conversions happen simultaneously
Real-time: Updates happen as you type, no button clicks required

// Bidirectional Conversion Logic:
kilometers = AU × 149,597,870.7
AU = kilometers ÷ 149,597,870.7

// Example 1: Type "1" in AU
kilometers = 1 × 149,597,870.7 = 149,597,870.7 km

// Example 2: Type "300,000,000" in kilometers
AU = 300,000,000 ÷ 149,597,870.7 ≈ 2.005

📊 Solar System Distances in AU

Planet/Celestial Body	Average Distance (AU)	Kilometers (approx.)
Mercury	0.39 AU	58 million km
Venus	0.72 AU	108 million km
Earth	1.00 AU	149.6 million km
Mars	1.52 AU	227.9 million km
Jupiter	5.20 AU	778 million km
Saturn	9.58 AU	1.43 billion km

❓ Frequently Asked Questions

Q: What is an astronomical unit (AU)?

A: An astronomical unit is the average distance between Earth and the Sun, approximately 149.6 million kilometers or 92.96 million miles.

Q: How accurate is the AU to km conversion?

A: We use the standard value of 1 AU = 149,597,870.7 km, which is the exact value defined by the International Astronomical Union.

Q: Why use AU instead of kilometers for astronomical distances?

A: AU provides more manageable numbers for solar system distances. For example, Jupiter is 5.2 AU rather than 778,000,000 km.

Q: Can I convert very large AU values?

A: Yes! This converter can handle any value up to 10¹⁵ AU. For interstellar distances, light-years are more commonly used.

🌠 Astronomical Scale Reference

Understanding the scale:

1 AU = Distance from Earth to Sun
1 light-second ≈ 0.002 AU
1 light-minute ≈ 0.12 AU
1 light-hour ≈ 7.21 AU
1 light-year ≈ 63,241 AU

Note: For distances beyond our solar system, light-years are more commonly used than AU.