Free Birth Chart Calculator
& Astrology Tools

Most people meet astrology through their Sun sign, the one you get from your birthday alone. It is a real part of the picture, but it is roughly a twelfth of it. A birth chart is the whole sky at the moment you were born, and it needs three pieces of information to build: your date of birth, your time of birth, and the place. With those, the birth chart calculator will place every planet in a sign and a house, draw the aspects between them, and give you your rising sign and midheaven.

If you only remember three things from your chart, make them your Sun, your Moon, and your Rising sign. The Sun describes what you are built around, the core motivation that stays constant. The Moon covers your emotional wiring, what soothes you and what sets you off, and it is usually the placement people recognize instantly once it is explained. The Rising sign, or ascendant, is the mask and the doorway: how you come across before anyone knows you, and the thing that decides the entire house layout of your chart.

A chart reads like a sentence with three parts. The planet is what is happening, the sign is how it happens, and the house is where in your life it shows up. Mars in Gemini in the tenth house is drive, expressed through words and quick pivots, aimed at career and public standing. Once that grammar clicks, the rest of the chart stops looking like a wheel of symbols and starts reading like a description of someone you know.

The lines drawn across the middle of the wheel are aspects, the angles between planets. Conjunctions fuse two drives together, squares create the friction that usually produces the most growth, trines give you something that comes easily enough that you might not notice it, and oppositions ask you to hold two things in balance. Nobody has a chart without hard aspects, and a chart full of easy ones is not a better life, just a different set of problems.

Your natal chart never changes, but the sky keeps moving. Comparing today's positions against your birth positions is what transits measure, and it is the standard way astrologers talk about timing. Slow planets matter most here. A Saturn transit to a personal planet lasts months and tends to coincide with the periods people later describe as the ones that made them grow up.

For relationships, synastry overlays two charts and reads the contacts between them, while a composite chart treats the relationship itself as a third entity with its own chart. If you want to see the year ahead, a solar return is cast for the exact moment the Sun comes back to its birth degree. Every one of these tools on this site is free and needs no account.

Interpretation is where astrologers disagree, but the positions underneath should not be up for debate. Every chart here is computed with the Swiss Ephemeris, the same high precision library professional astrology software runs on, with proper historical timezone handling so a birth during a daylight saving change lands on the right minute. Our astrology calendar is generated the same way: eclipse and retrograde times are scanned straight out of the ephemeris rather than copied from another site.

If you want the full detail on how the pipeline works, which house system we default to, and where the method has real limits, we documented it on the methodology page.