Pi
3.141592653589793Circumference divided by diameter.
SCIENTIFIC MATH / ONE CLEAR STEP AT A TIME
Math constants
A small reference shelf for numbers that show up everywhere.
12 constants
Euler’s number
2.718281828459045The base of natural logarithms.
Golden ratio
1.618033988749895The positive solution of x² = x + 1.
Square root of two
1.414213562373095The diagonal of a unit square.
Euler–Mascheroni constant
0.577215664901533The limiting difference between harmonic sums and the natural log.
Square root of three
1.732050807568877Twice the height of a unit equilateral triangle.
Tau
6.283185307179586Two pi: one complete turn in radians.
Apéry’s constant
1.202056903159594The sum of reciprocal positive integer cubes.
Catalan’s constant
0.915965594177219An alternating sum of reciprocal odd squares.
Glaisher–Kinkelin constant
1.282427129100623Appears in products and asymptotic expansions.
Feigenbaum alpha
2.502907875095893Magnitude of a universal spatial-scaling constant.
Feigenbaum delta
4.669201609102990A universal scaling ratio in period doubling.
No matching constants. Try “pi” or “root”.
THE IDEA BEHIND THE ANSWER
A reference, ready when you are.
Useful constants, ready to copy
Values are rounded to the displayed precision, not arbitrary-precision representations.
GOOD TO KNOW
Using this reference
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