Main rules

➤ use square brackets [ ] for expressions. For example: [2+2].
➤ input name of a variable before expression following by ":". For example: [x:2+2], variable x will have the value 4.
➤ press Enter in any place of an expression or just after the last square bracket to calculate a value.
➤ use variables in your expressions. For example: [10*x].
➤ move cursor or click on an expression to edit it.


Expresso recognizes all common mathematical operators:

Operator Function Description
Standard Operators
+ add addition and unary positive
- or subtract and negate subtraction and negation
* or × multiply multiplication
/ or ÷ divide division
% mod or percent modulus or a percentage of a value
! factorial factorial
^ pow exponentiation
º or ° dtor converts the value to radians
Bitwise Operators
& and bitwise and
| or bitwise or
^^ xor bitwise xor
~ not bitwise not
<< lshift bitwise left shift
>> rshift bitwise right shift
Comparison Operators
== or = l_eq equal
!= l_neq not equal
< l_lt less than
> l_gt greater than
<= or l_ltoe less than or equal
>= or l_gtoe greater than or equal
Logical Operators
&& or l_and logical and
|| or l_or logical or
! or ¬ l_not logical not


In addition the following functions are available:

Functions that take > 1 parameter

  • sum() - returns a sum of the passed parameters
  • count() - returns the number of passed parameters
  • min() - returns the minimum of the passed parameters
  • max() - returns the maximum of the passed parameters
  • median() - returns the median of the passed parameters
  • stddev() - returns the standard deviation of the passed parameters
  • average() - returns the average of the passed parameters
  • random() - returns a random integer. Can take 0, 1, or 2 parameters. The first parameter (if given) is the lower bound of the random integer. The second parameter (if given) is the upper bound of the random integer.
  • nthroot() - returns the nth root of a number. For example, nthroot(27,3) returns the cube root of 27, or 3.

Functions that take 1 parameter:

  • sqrt() - returns the square root of the passed parameter
  • log() - returns the base 10 log of the passed parameter
  • ln() - returns the base e log of the passed parameter
  • log2() - returns the base 2 log of the passed parameter
  • exp() - returns e raised to the power of the passed parameter
  • ceil() - returns the passed parameter rounded up
  • floor() - returns the passed parameter rounded down
  • The trigonometric functions:

    • sin(), cos(), tan()
    • Their inverses (asin, acos, atan)
    • Their reciprocals (csc, sec, cotan)
    • The reciprocals of the inverses (acsc, asec, acotan)
    • The hyperbolic variations of all the above functions (sinh, cosh, tanh, asinh, acosh, atanh, csch, sech, cotanh, acsch, asech, acotanh)
    • The versine functions (versin, vercosin, coversin, covercosin, haversin, havercosin, hacoversin, hacovercosin, exsec, excsc, crd)
  • dtor() - converts the passed parameter from degrees to radians
  • rtod() - converts the passed parameter from radians to degrees

Functions that take no parameters ("constant functions"):

  • phi - returns the value of ϕ (the Golden Ratio). Also recognized as ϕ
  • pi - returns the value of π. Also recognized as π
  • pi_2 - returns the value of π/2
  • pi_4 - returns the value of π/4
  • tau - returns the value of τ. Also recognized as τ
  • sqrt2 - returns the value of the square root of 2
  • e - returns the value of e
  • log2e - returns the value of the log base 2 of e
  • log10e - returns the value of the log base 10 of e
  • ln2 - returns the value of the log base e of 2
  • ln10 - returns the value of the log base e of 10