Moon Percentage Calculator



The Moon Percentage Calculator is a valuable online tool designed to decipher the percentage of the moon that is illuminated at any given time during its orbit around Earth. This information is essential for astronomers, stargazers, and anyone interested in understanding the moon’s changing appearances.


The calculation behind the Moon Percentage Calculator is straightforward:

Moon Illumination Percentage (MIP) = (Illuminated Moon Area / Total Moon Area) x 100


  • MIP is the Moon Illumination Percentage.
  • Illuminated Moon Area is the area of the moon currently lit by the sun.
  • Total Moon Area is the moon’s complete surface area.

How to Use?

Utilizing the Moon Percentage Calculator is a breeze:

  1. Select Date and Time: Enter the specific date and time for which you want to determine the moon’s illumination percentage.
  2. Calculate: Click the calculate button to obtain the moon’s illumination percentage for the chosen date and time.
  3. Interpret Results: Review the calculated moon illumination percentage, which indicates how much of the moon’s surface is currently lit.


To illustrate the usage of the Moon Percentage Calculator, let’s consider an example:

Suppose you want to know the moon’s illumination percentage on December 15th, 2023, at 8:00 PM UTC. Using the calculator:

  • Enter the date as December 15, 2023.
  • Set the time to 8:00 PM UTC.
  • Click the calculate button.

The calculator will provide you with the precise moon illumination percentage for that date and time, which will vary depending on the moon’s position in its orbit.


Q1: Why is it essential to know the moon’s illumination percentage? A1: The moon’s illumination percentage helps astronomers and enthusiasts track lunar phases, aiding in celestial observations and lunar event planning.

Q2: How does the moon’s illumination percentage affect Earth? A2: Lunar phases impact tides on Earth due to gravitational forces. Full moons and new moons tend to result in higher tidal ranges.

Q3: Can the Moon Percentage Calculator predict eclipses? A3: No, this calculator determines lunar illumination percentage but does not predict eclipses. Eclipses are more complex events that involve the alignment of the sun, moon, and Earth.


The Moon Percentage Calculator provides a valuable window into the ever-changing lunar landscape. By revealing the moon’s illumination percentage at any given moment, it empowers astronomers, skywatchers, and curious individuals to connect with the celestial rhythms that have fascinated humanity for centuries. Understanding lunar phases not only enriches our knowledge of the cosmos but also influences activities such as stargazing, astronomy, and even gardening, making it a versatile tool for both amateur and professional enthusiasts of the night sky.

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