FLOOR

FLOOR(number, significance)

Returns the number rounded to the nearest integer or multiple.

number	The number to be rounded.
significance	The multiple you want the number rounded to.

REMARKS

* FLOOR.MATH was added in Excel 2013 to replace this function.
* This function is only available for backwards compatibility and should not be used.
* Positive decimal numbers with a positive significance are rounded down.
* Positive decimal numbers with a negative significance returns #NUM!
* Negative decimal numbers with a positive significance are rounded down.
* Negative decimal numbers with a negative significance are rounded up.
* If "significance" = 0 and "number" <> 0, then #DIV/0! is returned.
* If "significance" = 0 and "number" = 0, then zero is returned.
* There was also a CEILING function that can round up positive numbers.
* This function has been available since Excel 1997.
* For the Microsoft documentation refer to support.microsoft.com

	A
1	=FLOOR(45, 50) = 0
2	=FLOOR(0.9, 1) = 0
3	=FLOOR(1.1, 1) = 1
4	=FLOOR(1.5, 1) = 1
5	=FLOOR(-1.5, 1) = -2
6	=FLOOR(1.1, 3) = 0
7	=FLOOR(3.1, 3) = 3
8	=FLOOR(3.1, -3) = #NUM!
9	=FLOOR(-1.99, -1) = -1
10	=FLOOR(-1.99, 1) = -2
11	=FLOOR(-1.99, 1) = -2
12	=FLOOR(8.26, 0.05) = 8.25
13	=FLOOR(0.234, 0.01) = 0.23
14	=FLOOR(NOW(), "0:20") = 3:20:00 PM
15	=FLOOR("text", 1) = #VALUE!
16	=FLOOR(15, 0) = #DIV/0!

1 - What is 45 rounded down to a multiple of 50.
2 - What is 0.9 rounded down to a multiple of 1.
3 - What is 1.1 rounded down to a multiple of 1.
4 - What is 1.5 rounded down to a multiple of 1.
5 - What is -1.5 rounded down to a multiple of 1.
6 - What is 1.1 rounded down to a multiple of 3.
7 - What is 3.1 rounded down to a multiple of 3.
8 - What is 3.1 rounded down to a multiple of -3. This returns #NUM!
9 - What is -1.99 rounded down to a multiple of -1. The minus sign is ignored, so this is the same as a multiple of plus 1.
10 - What is -1.99 rounded down to a multiple of 1.
11 - What is -1.99 rounded down to a multiple of 1.
12 - What is 8.26 rounded down to a multiple of 0.05.
13 - What is 0.234 rounded down to a multiple of 0.01.
14 - What is the current time rounded down to the nearest 20 minutes.
15 - If any of the arguments are not numeric.
16 - If significance is zero.