About Big 3 Calculator
Big 3 Calculator is a free astrology tool created by Cosmic by Design. It helps you identify your Sun, Moon, and Rising signs and begin understanding what they mean for you, in clear and beginner friendly language.
What the calculator uses
The calculator uses three details: your birth date, your birth time, and your birth location. From those, it calculates your Sun sign, Moon sign, and Rising sign and creates a personalized introduction to each one and how they begin to work together.
Your exact birth time matters most for your Rising sign, which changes roughly every two hours. If you do not know your birth time, the calculator currently gives you a Big Two reading based on your Sun and Moon signs instead of guessing.
Using the calculator is free and does not require an account. Learn more in our guide on why birth time matters for your Rising sign.
Created by Cosmic by Design
Cosmic by Design is an astrology practice focused on helping people make sense of themselves and the people in their lives, so they can move with more clarity. Big 3 Calculator is one of its free tools.
Go deeper
The free calculator is a starting point. If you want a personal interpretation of your combination, the Full Big 3 Reading is a 1:1 session with Cosmic by Design. You can also browse the Big 3 guides.
Find your Big 3
Enter your birth date, time, and location to calculate your Sun, Moon, and Rising signs for free.