Enter the number of days into the current lunar cycle and the average length of a lunar cycle into the calculator to determine the Moon Percentage.

## Moon Percentage Formula

The following formula is used to calculate the percentage of the moon that is illuminated at any given time.

MP = (DI / 29.53) * 100

Variables:

- MP is the Moon Percentage (%) DI is the number of days into the current lunar cycle (days)

To calculate the Moon Percentage, divide the number of days into the current lunar cycle by 29.53 (the average length of a lunar cycle in days). Multiply the result by 100 to convert the decimal to a percentage.

## What is a Moon Percentage?

A Moon Percentage refers to the amount of the moon’s surface that is illuminated and visible from Earth at a particular time. This percentage can range from 0% (new moon) to 100% (full moon). The moon’s phase, position in its orbit around the Earth, and the Earth’s position in its orbit around the sun all contribute to the moon percentage.

## How to Calculate Moon Percentage?

The following steps outline how to calculate the Moon Percentage.

- First, determine the number of days into the current lunar cycle (DI).
- Next, use the formula: MP = (DI / 29.53) * 100 to calculate the Moon Percentage.
- Finally, insert the value of DI into the formula and calculate the Moon Percentage.
- After calculating the result, check your answer with the calculator above.

**Example Problem:**

Use the following variables as an example problem to test your knowledge.

DI: number of days into the current lunar cycle (days) = 15