Moon Phase Percentage Calculator

Calculate Moon Phase Percentage

Formula

The formula to calculate the moon phase percentage is:

\[ \text{MPP} = \left( \frac{\text{DSNM}}{14.765} \right) \times 100 \quad \text{for DSNM} \leq 14.765 \]

\[ \text{MPP} = \left( \frac{29.53 - \text{DSNM}}{14.765} \right) \times 100 \quad \text{for DSNM} > 14.765 \]

Where:

What is Moon Phase Percentage?

Moon phase percentage indicates the fraction of the moon's disk that is illuminated by the sun and visible from Earth. The percentage varies in a predictable cycle as the moon orbits the Earth, and it can range from 0% (new moon) to 100% (full moon). Understanding the moon phase percentage is useful for various purposes, including astronomy, navigation, and planning outdoor activities at night.

Example Calculation 1

Let's assume the following value:

Using the formula:

\[ \text{MPP} = \left( \frac{10}{14.765} \right) \times 100 = 67.73 \]

The moon phase percentage is 67.73%.

Example Calculation 2

Let's assume the following value:

Using the formula:

\[ \text{MPP} = \left( \frac{29.53 - 20}{14.765} \right) \times 100 = 64.77 \]

The moon phase percentage is 64.77%.