Natal Chart

What a birth chart is

A birth chart is a map of the sky from one place, at one moment — the moment you were born. It records where each of the ten classical bodies sat along the ecliptic, which sign each occupied, and how they angled to one another.

Everything else in astrology is built on it. Transits are read against it; synastry compares two of them; a horoscope column is a very compressed reading of one twelfth of it.

The three layers to read first

Planets — what. The Sun is your core drive, the Moon your private needs, Mercury how you think, Venus what you value, Mars how you act. The outer planets move too slowly to distinguish you from everyone born the same year, and are read by house rather than sign.

Signs — how. A planet in a fire sign behaves differently from the same planet in an earth sign.

Houses — where. The twelve houses divide the chart by life area, and are the layer that requires an accurate birth time.

Why the time matters, and what happens without it

The ascendant — the degree rising on the eastern horizon — advances a full 360° every 24 hours, roughly one degree every four minutes. An hour's error moves it about half a sign, and the houses move with it.

Without a birth time you still get: every planet's sign (except possibly the Moon, if you were born near an ingress), and every aspect between them. You lose: the ascendant, the midheaven, and all twelve house placements. That is a real loss but not a fatal one — plenty of chart reading is done on planets and aspects alone.

House system

This chart uses equal houses, measured in thirty-degree segments from the ascendant. It is not the most common choice in modern software, which usually defaults to Placidus, and the reason for using it here is straightforward: equal house is defined at every latitude. Placidus breaks down above roughly 66° north or south, where it produces houses of wildly unequal size or none at all.

If you are comparing this chart to one from another site and the planets agree but the houses do not, the house system is almost certainly why.

Privacy

The chart is computed in your browser from the same ephemeris used throughout the site. Your birth date, time and location never leave the page and are not stored.