Moon Phase Calculator

The moon phase on any date can be calculated using the synodic period (29. 53 days) — the time for the Moon to return to the same phase

The calculator uses the standard published formula for moon phase. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches. You can enter values in the units shown — the calculator handles all conversions internally.

The calculator applies the standard formula for this type of calculation. See the 'How It Works' steps above for the detailed formula breakdown.