Excel TRUNC Function
The Excel TRUNC function returns a truncated number based on an (optional) number of digits. For example, TRUNC(4.9) will return 4, and TRUNC(-3.5) will return -3. The TRUNC function does no rounding, it simply truncates as specified.
- number - The number to truncate.
- num_digits - [optional] The precision of the truncation (default is 0).
Use the TRUNC function to remove the fractional part of a number and return just the integer. For example, TRUNC(4.9) will return 4, and TRUNC(-3.5) will return -3. TRUNC does not do any rounding, it simply returns the integer part of the number.
Example #1 - basic usage
Example #2 - set number of decimal places
TRUNC can also be used to return a set number of decimal places without rounding, using the num_digits argument. For example, TRUNC (PI(), 2) will return 3.14 and TRUNC (PI(), 3) will return 3.141.
TRUNC vs INT
TRUNC is similar to the INT function because they both can return the integer part of a number. However, TRUNC simply truncates a number, while INT actually rounds a number down to an integer. With positive numbers, and when TRUNC is using the default of 0 for num_digits, both functions return the same results. With negative numbers, the results can be different. INT(-3.1) returns -4, because INT rounds down to the lower integer. TRUNC(-3.1) returns -3. If you simply want the integer part of a number, you should use TRUNC.
Rounding functions in Excel
Excel provides a number of functions for rounding:
- To round normally, use the ROUND function.
- To round to the nearest multiple, use the MROUND function.
- To round down to the nearest specified place, use the ROUNDDOWN function.
- To round down to the nearest specified multiple, use the FLOOR function.
- To round up to the nearest specified place, use the ROUNDUP function.
- To round up to the nearest specified multiple, use the CEILING function.
- To round down and return an integer only, use the INT function.
- To truncate decimal places, use the TRUNC function.