We have often used the ceiling function in mathematical problems to round up a decimal number to next greater integral value. PHP provides us with a built-in function ceil() to perform such operation. The ceil() function is a built-in function in PHP and is used to round a number to the nearest greater integer.

Syntax:  

float ceil(value)

Parameters: The ceil() function accepts a single parameter value which represents the number which you want to round up to the nearest greater integer.

Return Value: The return type of the ceil() function is float as shown in the syntax. It returns the number which represents the value rounded up to the next highest integer. 

Examples:  

Input : ceil(0.70)
Output : 1

Input : ceil(-4.1)
Output : -4

Input : ceil(6)
Output : 6

Below programs illustrate the ceil() function in PHP:  

• When a positive number with decimal places is passed as a parameter:

Output: 

1

• When a negative number with decimal places is passed as a parameter:

Output: 

-4

• When a number with no decimal places is passed as a parameter:

Output: 

6

Reference: 
http://php.net/manual/en/function.ceil.php