What is the Math library in Arduino?

There are different libraries in Arduino that can be used for different uses, math.h is one of these libraries. The math.h library contains functions that are related to mathematics like getting square roots, finding trigonometric functions, and finding the power. These functions are very useful when someone is designing a calculator. Similarly, in the movements of robotics, we can find out the angles by using the trigonometric functions.

All these math built-in functions are included in the math.h library. In this write-up, the math library has been discussed in detail with the help of examples.

What are the macros of the math library

In Arduino, the default functions are pre-included in it. Like in c programming, if we have to use the string library, we have to include the header file of strings.h at the start of the code. These header files which are included in the code are known as “macros”.  In Arduino, the built-in libraries are by default included so there is no need to add them in the header files, we can simply use these macros libraries without including them in every code. The difference between the macros and functions is that functions are processed only when they are called whereas the macros are processed when the library is included.

The macro library of some of the most frequently used functions of math.h is:

Macros Value Explanation
M_E 2.71828 It is used for the exponent
M_LOG2E 1.4426 It is the value of the log of e to base 2
M_1_PI 0.318 It is the value of Pie
M_SQRT_2 1.414 It is the value of the square root of 2
fmodf It is used for the mode() function
fcosf It is used to for the acos() function
fsinf It is used to for the asin() function
ceilf It is used for the ceil() function

What are the functions of the math library in Arduino

The functions take the two input values and after performing some specific action on it, returns a single output. In the math library of Arduino, there are different functions, which take one or two input values and return a single output by performing a particular math operation on them. These math operations include finding the power, finding the mode, finding the cosine, and finding the other trigonometric operations.

The most commonly used math functions included in the math library of Arduino are explained in the table below:

Functions Explanation
cbrt(x) It will return the cube root of the x
copysign (value1, value2) It will return the value1 but with the sign of value2
exp(x) It will return the exponential value of the x
fabs(x) It will return the absolute value of x
floor(x) It will return the largest integral value less than or equal to x
ceil(y) It will return the smallest integral value which is equal to or larger than the given value of  y
fmax(value1,value2) It will return the maximum value among value1 and value2
fmin(value1,value2) It will return the minimum value among value1 and value2
pow(value1,value2) It will find the power of value1 according to value2
acos(x) It returns the value by calculating the arc cosine of x in the range of zero to pi and if the answer is out of range, it will generate domain error

How to use math.h library functions in Arduino

For a better understanding of the math functions in the math library of Arduino, consider the following Arduino code:

double x=10.0, y=20.0, z=-5.0;
void setup(){
Serial.print(“The cube root of x is:);
Serial.print(“The value of x is:);
Serial.print(“The exponent of x is:);
Serial.print(“The absolute of z is:);
Serial.print(“The ceil value of x is:);
Serial.print(“The floor value of x is:);
Serial.print(“The value of x is:);
Serial.print(“The maximum value among x and y is:);
Serial.print(“The minimum value among x and y is:);
Serial.print(“The power of x accordion to y is:);
Serial.print(“The arc cosine of x is:);
void loop(){

The output of the above code is:

In the above code, we have declared three variables x,y, and z with some values. We perform different functions with the help of math.h library and display the results on serial monitor output through the serial communication at baud rate of 9600. In the output, the result of the power function is “ovf” (overflow) which means the result is beyond the range. Similarly, in the result of acos() function, it returns nan(not a number) which means the value is a negative integer.


The math library in Arduino contains the functions related to maths. These functions provide the ease of doing mathematical operations; both arithmetic and trigonometric. This library is very important when you are designing a project in which mathematical calculations are included. In this write-up, we have discussed the math library which is by default included in Arduino. And also explain the functions of math.h library with the help of examples in Arduino.

About the author

Hammad Zahid

I'm an Engineering graduate and my passion for IT has brought me to Linux. Now here I'm learning and sharing my knowledge with the world.