Zodiac Sign Calculator

Work out zodiac sign instantly with clear inputs, formula shown and shareable results.

About Zodiac Sign Calculator

Western zodiac signs run between fixed calendar cutoffs, most falling between the 19th and 23rd of each month. A 4 September birthday is Virgo, an Earth sign, with the cusp into Libra on 23 September. The cutoffs drift by a day between years because the tropical year is not a whole number of days.

Formulas

Sign determination

compare the birth day against the cutoff date for that month

Elements

Fire, Earth, Air and Water each cover three signs

Worked example

With the default values below, Zodiac Sign Calculator returns Birth Day Used of 4. Change any input above and every figure here is recalculated in your browser.

Inputs used

Birth monthaccepts 1–12: 9
Birth dayaccepts 1–31: 4

Results

Birth Day Used: 4
Zodiac Sign: Virgo
Associated Element: Earth
Days Until The Sign Changes: 19

Step by step

1Values used
2Sign determination
3Elements
4Birth Day Used= 4
5Zodiac Sign= Virgo
6Associated Element= Earth
7Days Until The Sign Changes= 19

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why do published cusp dates differ by a day?

Because the Sun's entry into each sign shifts a few hours each year against the calendar, so the boundary date varies between years.

Do the signs match the actual constellations?

No longer. Precession has shifted the constellations by roughly one sign since the system was fixed about 2000 years ago.