Forms offers a very powerful option to calculate values. When defining the equation to calculate the result, you may pick from a list of questions in your form to use the response entered by a user. For example, if the form asks, “How many club shirts do you want?” and has a read-only “Cost per club shirt” field with a default value of 12.50, the form can calculate and display the total cost after tax (quantity * cost * 1.0825).
Results are rounded to only 2 decimal places, as would be typically used for calculating monetary values.
Operators
In addition to the add, subtract, multiple, and divide operators offered on the calculator, the following operator is also supported:
- ^ (e.g. 2^5 = 32)
Field Values
A value entered in the form by someone or the value configured for a selected option can be used in an equation. When used, these values are enclosed in double square brackets in the equation (e.g. “[[field_1234]]”). If the value associated with a response can not be successfully interpreted as a number, its value it set to zero.
When a form question allows selection of multiple checkboxes as a response, the value used in the equation will be the sum of all values associated with the selected checkboxes.
Functions
Buttons are provided for a limited number of common functions. These functions all accept a comma-separated list of values within the parentheses. For example, MIN(5,[[field_1]],[[field_2]]) will look at the value entered for two fields in the form, then return the lowest of those or ‘5’ if 5 is lower than either field value.
- SUM() – Calculate the sum of all values in a comma-separated list of values
- AVG() – Calculate the average of a comma-separated list of values
- MIN() – Find the highest value in a comma-separated list of values
- MAX() – Find the lowest value in a comma-separated list of values
The following functions can also be used by simply typing the function into the equation. Follow the links for details about how to use each function. Note the linked documentation may use slightly different names for the functions. Where they differ, Calculated Values in forms should use the function name listed here rather the name shown in the attached documentation. For example, use “logTen” rather than “log10”.
- abs() – Absolute value
- aCos() – Arc cosine
- aCosH() – Inverse hyperbolic cosine
- aSin() – Arc sine
- aSinH() – Inverse hyperbolic sine
- aTan() – Arc tangent
- aTanH() – Inverse hyperbolic tangent
- aTanTwo() – Arc tangent of two variables
- ceil() – Round fractions up
- cos() – Cosince
- cosH() – Hyperbolic cosine
- degToRad() – Converts the number in degrees to the radian equivalent
- en()
- exp() – Calculates the exponent of e
- expMOne() – Returns exp(number) – 1, computed in a way that is accurate even when the value of number is close to zero
- floor() – Round fractions down
- fMod() – Returns the floating point remainder (modulo) of the division of the arguments
- hypot() – Calculate the length of the hypotenuse of a right-angle triangle
- log() – By default this is Natural Log. If you want to use an alternate base such as Base 10, add “,10” before the closing parenthesis.
- logOneP() – Returns log(1 + number), computed in a way that is accurate even when the value of number is close to zero
- logTen() – Base-10 logarithm
- pow() – Exponential expression
- radToDeg() – Converts the radian number to the equivalent number in degrees
- round() – Rounds a float
- sin() – Sine
- sinH() – Hyperbolic sine
- sqrt() – Square root
- tan() – Tangent
- tanH() – Hyperbolic tangent
Constants
The following constants may also be used in an equation. For example, typing “2*pi” as the equation will return the value 6.2831853072 which will be rounded to two decimal places when displayed as “6.28”.
- e = 2.718281828459
- euler = 0.57721566490153
- lnPi = 1.1447298858494
- lnTen = 2.302585092994
- lnTwo = 0.69314718055995
- logTenE = 0.43429448190325
- logTwoE = 1.442695040889
- onePi = 0.31830988618379 (1/π)
- pi = 3.1415926535898 (π)
- piFour = 0.78539816339745 (π/4)
- piTwo = 1.5707963267949 (π/2)
- sqrtOneTwo = 0.70710678118655
- sqrtPi = 1.7724538509055
- sqrtThree = 1.7320508075689
- sqrtTwo = 1.4142135623731
- twoPi = 0.63661977236758
- twoSqrtPi = 1.1283791670955