☽ Free Lunar Return Chart Calculator

Umbriel's free lunar return calculator casts the chart for the moment the Moon comes back to its natal degree, roughly every twenty-seven and a third days, and read as a chart for that month.

A lunar return is the same idea as a solar return on a much shorter cycle. The Moon comes back to the exact degree it held at your birth every 27.32 days, and the chart for that moment is read as a picture of the month that follows.

Because it happens thirteen times a year, it is a working tool, not an annual event: practitioners use it the way you might use a weather forecast, and it is one of the few techniques that produces a fresh whole chart often enough to check against your own experience.

It needs an accurate birth time more than most. The return moment is derived from your natal Moon's exact degree, and the Moon moves about half a degree an hour, so a birth time out by an hour moves the return by about an hour too, and the return chart's Ascendant by around fifteen degrees, sometimes forty. Often a different rising sign, from an hour's error.

As with the solar return, where you cast it is a live question. Umbriel lets you set the location rather than assuming your birthplace.

The return moment also gets three facts about the Moon itself: its phase, whether it is void of course, and whether it is out of bounds. Each has its own tool if you want to look further.

When to use it. Use a lunar return when you want a whole chart for one month rather than for a year. People cast it as the month begins to see which house the Moon falls in and which sign is rising, to compare this month with the last, or to look back at a month that has already happened and check the chart against it. The solar return covers a year, the progressed Moon moves about a sign in two and a half years, and current transits show the sky against your birth chart; the lunar return is a fresh chart every month, cast for a moment of its own.

The three Moon readings, exactly. The phase is one of eight named phases, from New Moon to Waning Crescent, worked out from how far the Moon is ahead of the Sun, and shown with the percentage of the Moon that is lit. Void of course is answered on the default medieval rule used by the Void of Course Moon tool: the Moon is void when it has made its last conjunction, sextile, square, trine or opposition to the Sun, Mercury, Venus, Mars, Jupiter or Saturn and has not yet left its sign. Out of bounds means the declination of the Moon lies beyond the furthest reach of the Sun, north or south, about 23 degrees 26 minutes, the same test as on the declinations page. All three are read at the return moment, not averaged over the month, and they are left out when there is no birth time.

The return is found by searching for the instant the Moon's longitude equals its natal longitude, refined to the second rather than interpolated from a daily table. The Moon moves too fast for a table to be good enough here. Because the Moon's motion is uneven, the interval between returns is not constant, so each one is solved for individually rather than stepped forward by a fixed 27.32 days. Every pass is listed, so a month with an awkward boundary is visible, not rounded away.