TRUNC Function (OpenOffice Calc)
The TRUNC function in OpenOffice Calc removes the fractional part of a number by truncating toward zero. Learn syntax, behavior with negative numbers, examples, and best practices.
Verification status: Consult the documentation and examples below. Native application testing has not been documented for this guide. How formula examples are checked
The TRUNC function in OpenOffice Calc removes the fractional part of a number by truncating it toward zero. Unlike INT, which always rounds downward, TRUNC simply chops off the decimals without changing the sign direction.
What the TRUNC Function Does
- Removes the decimal portion of a number
- Always rounds toward zero
- Works with positive and negative numbers
- Useful for ID extraction, integer math, and formatting logic
- Works across sheets
TRUNC is ideal when you need clean integer extraction without directional rounding.
Syntax
TRUNC(number)
Arguments:
- number — Any numeric value or formula result
TRUNC is different from INT:
- TRUNC → toward zero
- INT → toward negative infinity
Behavior With Positive and Negative Numbers
| Input | TRUNC Result | Explanation |
|---|---|---|
| 7.9 | 7 | Fraction removed |
| 7.1 | 7 | Fraction removed |
| -7.1 | -7 | Toward zero |
| -7.9 | -7 | Toward zero |
This makes TRUNC safer than INT when working with negative values.
Basic Examples
Remove decimals from a number
=TRUNC(7.9)
Result: 7
Truncate a negative number
=TRUNC(-7.9)
Result: -7
Truncate a formula result
=TRUNC(A1 / B1)
TRUNC with cell reference
=TRUNC(A1)
Advanced Examples
Extract integer part of a division
=TRUNC(A1 / 12)
Useful for converting months to years, items to boxes, etc.
TRUNC for ID or code extraction
=TRUNC(A1)
Useful when numeric IDs contain decimals due to import issues.
TRUNC for date/time calculations
Extract whole days from a datetime:
=TRUNC(A1)
TRUNC across sheets
=TRUNC(Sheet1.A1)
TRUNC for pagination logic
Page number from row:
=TRUNC((ROW()-1) / 50) + 1
TRUNC for random integer ranges
=TRUNC(RAND() * 100)
Returns 0–99.
TRUNC with optional decimal places (LibreOffice only)
LibreOffice supports:
TRUNC(number; digits)
OpenOffice Calc does not support the second argument.
Comparison: TRUNC vs INT vs FLOOR
| Function | Rounds Toward | Example: -7.1 | Notes |
|---|---|---|---|
| TRUNC | 0 | -7 | Removes decimals |
| INT | −∞ | -8 | Always down |
| FLOOR | −∞ | -8 | Down to a multiple |
TRUNC is the most neutral of the three.
Common Errors and Fixes
TRUNC returns Err:502 (Invalid argument)
Occurs when:
- Input is text
- Input is empty
- A malformed reference is used
TRUNC returns unexpected values
Possible causes:
- Confusing TRUNC with INT
- Text numbers not converted to numeric
- Hidden spaces in cells
TRUNC ignores values you expected it to include
TRUNC ignores:
- Text numbers (
"123") - Empty cells
- Logical values
- Errors
TRUNC includes values you expected it to ignore
TRUNC includes:
- Dates
- Times
- Numeric results of formulas
Err:508 — Missing parenthesis
Usually caused by:
- Missing
) - Using commas instead of semicolons
Best Practices
- Use TRUNC when you need neutral truncation
- Use INT when rounding must go downward
- Use FLOOR when rounding to a multiple
- Convert imported text numbers to real numbers
- Use named ranges for cleaner formulas