Greek Small Letter Tau

τ
Symbol Format Data
τ Code Point
U+03C4
TeX
\tau
SVG

Usage

The Greek small letter τ (tau) is used in math as the circle constant to represent a full rotation around a circle in radians. The value of is approximately and can be calculated by dividing any circle’s circumference by its radius. Typically, the symbol appears in an expression like this:

This expression is a formula for the area of a circle. In plain language, this expression can be read as: the area of the circle is equal to one-half multiplied by the constant (tau) multiplied by the radius of the circle squared.

Related

The capital Greek letter Τ (capital tau).

Links

The circle constant τ (tau) is a geometric constant approximately equal to 6.283. The numeric value is defined as the length of any circle's circumference divided by the length of its radius.

The radian angle system is a unit of measure for angles. To measure an angle in radians, divide the arc length of the angle by the radius used to draw the arc. A full rotation is equal to 2π radians.

The area of a circle is given by the geometric constant π (pi) multiplied by the radius of the circle squared (A = πr²).

The circumference of a circle is given the constant π (pi) multiplied by two times the radius of the circle.