ROUND vs INT vs TRUNC: they disagree below zero
On positive numbers these three feel interchangeable and people use whichever they learned first. The differences bite with negatives and with digits: INT always rounds DOWN (toward minus infinity), TRUNC just deletes decimals (toward zero), and only ROUND actually rounds.
The differences at a glance
| ROUND | INT | TRUNC | |
|---|---|---|---|
| 2.7 | 3 (nearest) | 2 (down) | 2 (chop) |
| -2.5 | -3 (away from zero on .5) | -3 (down = more negative) | -2 (toward zero) |
| Keep some decimals | Yes — digits argument | No — integers only | Yes — TRUNC(x,2) chops to 2 decimals without rounding |
| Use for | Money, display-safe values | Bucketing, whole units, MOD-style math | Cutting precision without changing direction |
| Compatibility | Universal | Universal | Universal — all three verified in every version we test |
Which should you use?
- ROUND — Anything financial or user-facing — it's the only one of the three that rounds. ROUNDUP/ROUNDDOWN when the direction must be fixed.
- INT — "How many whole units fit" and floor-style math — but remember INT(-2.5) is -3, which surprises people processing refunds or temperature data.
- TRUNC — Dropping decimals while keeping sign symmetry — TRUNC(-2.5) is -2, mirroring TRUNC(2.5)=2. Also the safe way to strip the time from a date-time serial.
Compatibility (from executed tests)
All three execute identically in every version of Excel, Google Sheets, and LibreOffice we test, including the negative-number edge cases — the differences are mathematical, not cross-app. (FLOOR and CEILING have messier cross-version stories; see their function pages.)
Example formulas
| Round to cents | =ROUND(A2,2) |
| Whole units (floor) | =INT(A2) |
| Strip time from a datetime | =TRUNC(A2) |
Full per-version details on each function page: ROUND · INT · TRUNC.