Mercury in Astrology: How You Think and Talk
Mercury describes how your mind works: how you take in information, how you talk, write and argue, and how you learn. It is never more than 28 degrees from the Sun, so your Mercury is always in your Sun sign or one of the two signs either side of it.
| Type | Personal planet |
|---|---|
| Rules | Gemini and Virgo |
| Exalted in | Virgo |
| Detriment in | Sagittarius and Pisces |
| Fall in | Pisces |
| Full cycle | About one year through all twelve signs |
| Time in each sign | Two to four weeks, longer when retrograde |
| Retrograde | Three times a year, about three weeks each |
What Mercury describes in a birth chart
Mercury is the messenger. In a birth chart it rules perception, reasoning, curiosity, speech, writing, trade and short journeys. Two people with the same Sun sign can think in completely different ways because their Mercury sits in a different sign.
Mercury rules Gemini and Virgo, the two signs most concerned with information, one gathering it and one sorting it. A strong Mercury does not mean high intelligence; it describes the style of intelligence, whether fast and associative, slow and thorough, persuasive or precise.
Mercury in the twelve signs
In fire signs Mercury thinks fast and speaks first. In earth signs it wants evidence and practical use. In air signs it loves ideas for their own sake and talks to think. In water signs it reads tone and feeling before the words. Mercury in Sagittarius and Pisces is traditionally weaker at detail and stronger at the big picture.
Mercury in the houses
Mercury's house shows where your attention goes most naturally. In the third house it is busy with siblings, neighbours and daily messages; in the sixth with work processes; in the ninth with study, travel and big questions; in the tenth with a public voice.
Mercury's aspects
Mercury aspects to Mars sharpen speech and make arguments quicker. Saturn aspects make thinking careful and serious. Jupiter aspects widen it, sometimes at the expense of detail. Neptune aspects make it imaginative and harder to pin down.
Mercury in relationships
Mercury contacts between two charts show how easily two people understand each other. Mercury in signs of the same element usually means conversations flow; a square between two Mercurys often means each person has to translate the other.
Mercury in transit
Mercury's retrograde periods are the best-known transit in astrology: three or four times a year Mercury appears to move backwards against the stars for around three weeks. Astrologers treat these as times to review, repair and re-read rather than to launch, sign or buy anything important.
Common questions
Why is my Mercury never far from my Sun?
Mercury orbits inside Earth's orbit, so from Earth it never appears more than about 28 degrees from the Sun. It is in your Sun sign or one of the two neighbouring signs.
Is Mercury retrograde bad?
It describes a period of review. Plans made then tend to need revisiting, so many people use it to finish and correct rather than to start.
Find yours
Find the sign your Mercury was in and what it says about how you think and talk. Mercury sign calculator
See what Mercury is doing in your chart this week
Mercury aspects your natal planets several times a month. A Precision Horoscope names the ones that touch you today. Get my free personal reading