Drops the fractional part of a number without rounding.
TRUNC(<number>)
TRUNC(<number>, <decimals>)
It simply cuts off the extra digits: 4.9 becomes 4, and -4.9 becomes -4 — always towards zero. The second argument keeps the number of decimal places you need, like ROUND, but without rounding.
orders
| id | created_at | amount |
|---|---|---|
| 1 | 2026-07-03 10:15:00 | 120.50 |
| 2 | 2026-07-28 18:40:00 | 80.25 |
| 3 | 2026-08-09 09:05:00 | 199.99 |
| 4 | 2026-08-21 14:30:00 | 45.00 |
| 5 | 2026-09-02 11:00:00 | 64.75 |
These tables already exist in the sandbox — the examples below use them. Want to try this in your own database? Copy the SQL.
| positive | negative | two_digits |
|---|---|---|
| 4 | -4 | 19.85 |
| id | amount | rounded | truncated |
|---|---|---|---|
| 1 | 120.50 | 121 | 120 |
| 2 | 80.25 | 80 | 80 |
| 3 | 199.99 | 200 | 199 |
| 4 | 45.00 | 45 | 45 |
| 5 | 64.75 | 65 | 64 |
120.50 rounds to 121 but truncates to 120.
Don't confuse it with FLOOR for negative numbers: TRUNC(-4.9) gives -4, while FLOOR(-4.9) gives -5.
TRUNC(x, 2) exists only for numeric: for double precision you'll get function trunc(double precision, integer) does not exist. Cast the type: TRUNC(x::numeric, 2).
In PostgreSQL, TRUNC doesn't truncate dates — that's a habit from Oracle. To cut a date down to the month or day, use DATE_TRUNC.