# Moon Phase Calculator

> Find the moon phase, illumination and age for any date, plus the upcoming new and full moons.

The moon phase depends on how far through the 29.53-day synodic month a date falls, measured from a known new moon. This calculator gives the phase name, the illuminated percentage, the moon's age in days, and the dates of the next new and full moons.

**URL:** https://convertto.tech/t/moon-phase-calculator
**Category:** Date & Time Tools (https://convertto.tech/c/date-time-tools)
**Privacy:** Runs entirely in the browser; no upload
**Cost:** Free, no sign-up
**Last updated:** 2026-08-01

## Key facts

- **Privacy:** Runs entirely in your browser — nothing is uploaded
- **Cost:** Free, unlimited, no sign-up

## How to use

1. Enter or paste your date.
2. Set the show the next.
3. The result appears immediately — copy or download it.

## FAQ

### Why is the moon sometimes visible in daylight?

Because its position relative to the sun, not its brightness, determines when it is up. Around first and last quarter the moon is roughly 90 degrees from the sun, which puts it in the daytime sky for half its orbit.

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