Free Big 3 calculator
Your Big 3, in one go
One form, three cards: your Sun, Moon, and rising sign with exact degrees — what you're growing into, how you feel, and how you arrive. No birth time? You get an honest two out of three.
Free. Computed on your device — nothing about your birth is sent anywhere.
Your Big 3 in astrology is your Sun, Moon, and rising sign — what you're growing into, how you feel, and how you come across on arrival. Enter your birth date, time, and place and this free calculator returns all three as cards with exact degrees, computed in your browser with the same engine as the MoonQ app. Without a birth time it gives you Sun and Moon and honestly leaves the rising blank.
Calculate your Big 3
Everything is computed on your device with the same engine as the MoonQ app — nothing about your birth leaves this page.
A worked example
So the page is useful even with JavaScript off, here are the three cards the calculator produces for one documented example birth — computed and verified against the MoonQ app's engine at build time.
4 July 1991, 4:00 PM — Austin, Texas
Computed live by the MoonQ astro-engine — identical to the iOS app engine (verified to < 1e-9°). Tropical zodiac. Birthplace coordinates from GeoNames (CC BY 4.0).
How to read your three cards together
Sun — the direction
Your Sun sign is the slow, steady one — it changes only with the calendar month. Read it as what you're growing into: the theme your life keeps returning to when you have the energy to choose.
Moon — the weather
Your Moon sign is your inner climate: how feelings arrive, what safety feels like, how you recharge. It changes sign every ~2.3 days, which is why it needs more than a star-sign column can give it.
Rising — the doorway
Your rising sign is how you arrive before anyone knows the other two. It changes every ~2 hours, sets your houses, and is the reason the calculator asks for a birth time — and honestly manages without one.
Big 3 facts worth knowing
- The trio
- Sun (identity & direction) · Moon (feelings & needs) · Rising (arrival & first impressions)
- How fast each moves
- Sun: one sign a month · Moon: one sign every ~2.3 days · Rising: one sign every ~2 hours
- What needs a birth time
- Only the rising — Sun and Moon come from date and place alone on most days
- Without a time
- Sun + Moon cards, rising honestly blank — the same fallback the MoonQ app uses
- Why they differ site to site
- House system and zodiac choices; MoonQ uses the tropical zodiac and whole-sign houses, stated openly
- Engine parity
- Identical to the MoonQ iOS app engine (verified to < 1e-9°)
Why the Big 3 is the fastest way into a chart
A full birth chart places ten bodies, twelve houses, and a web of aspects — wonderful, and a lot on first meeting. The Big 3 is the same chart read at a glance: one slow mover (Sun), one fast mover (Moon), one place-and-minute mover (rising). Between them they cover direction, weather, and doorway — which is why "what's your Big 3?" has replaced "what's your sign?" for a generation raised on it.
Because the three move at such different speeds, they're also honest in different ways. Your Sun is certain from your birthday alone. Your Moon is certain on most dates — except the days it changes sign, when only a birth time settles it. Your rising is never knowable without the time. This calculator applies exactly those rules, card by card, instead of pretending all three are equally easy.
When your three cards seem to contradict each other — a blazing Sun, a private Moon, a breezy rising — that's not an error. That's the interesting part, and it's precisely what the MoonQ app reads: how your three work together, in plain words, every day.
Big 3 questions
What are the Big 3 in astrology?
Your Big 3 are your Sun, Moon, and rising sign: the Sun for identity and direction, the Moon for feelings and needs, the rising for how you come across. Together they're the quickest honest sketch of a birth chart — three cards instead of a full wheel.
Do I need my birth time for my Big 3?
For your rising, yes — it changes about every two hours, so no time means no rising, and this calculator says so rather than guessing. Your Sun needs only your birth date, and your Moon usually does too (on days the Moon changed signs, a time settles which side of the edge you were born).
How do I read my Big 3 together?
Start with the Sun as the theme, the Moon as the weather, and the rising as the doorway. Apparent contradictions are normal and useful — a confident Sun with a tender Moon just means the theme and the weather differ. The three cards above show sign and degree; the MoonQ app reads how yours combine.
Why is my Big 3 different on different websites?
Almost always one of three reasons: a different house system, a different zodiac (tropical vs sidereal), or a silently assumed birth time. MoonQ uses the tropical zodiac and whole-sign houses — the same as the app — and never assumes a time it doesn't have, so what you see here matches what the app would tell you.
Is this Big 3 calculator really free?
Yes — free, no sign-up, and computed entirely on your device. The full reading of how your three signs work together lives in the MoonQ app, which uses the identical engine.
Three cards are the start — the conversation is the app
MoonQ reads your Sun, Moon, and rising together — daily, warmly, and in plain words. And when you're ready: who matches them.