Google Sheets TRUNC Function: Syntax, Examples & Tips

What Is TRUNC?

TRUNC cuts a number off at a chosen number of decimal places without rounding. =TRUNC(3.789, 1) returns 3.7, whereas =ROUND(3.789, 1) returns 3.8. TRUNC simply discards the digits beyond the cut point.

How TRUNC Works

• With places = 0 (the default), TRUNC removes the entire fractional part: TRUNC(8.99) is 8.
• With positive places, it keeps that many decimals: TRUNC(8.9876, 2) is 8.98.
• With negative places, it zeroes digits to the left of the decimal point: TRUNC(1789, -2) is 1700.
• TRUNC always moves towards zero, for both positive and negative numbers: TRUNC(-8.99) is −8.

TRUNC vs. INT vs. ROUND vs. ROUNDDOWN

The important difference is with negative numbers. INT rounds down to the next lower integer, so −7.8 becomes −8. TRUNC just drops the decimals, so −7.8 becomes −7. ROUNDDOWN also rounds toward zero, so for most purposes TRUNC(x, n) and ROUNDDOWN(x, n) give the same answer; the difference is that TRUNC's second argument is optional.

Basic Examples

Drop the decimals

=TRUNC(42.97)

Returns 42.

Keep two decimal places

=TRUNC(B2, 2)

If B2 is 19.9987, returns 19.99.

Truncate to the nearest hundred

=TRUNC(C2, -2)

If C2 is 4,567, returns 4,500.

Extract the date from a timestamp

=TRUNC(A2)

Because a timestamp is a date serial plus a time fraction, TRUNC removes the time and leaves the date. Format the result as a date.

Get the decimal part of a number

=B2 - TRUNC(B2)

If B2 is 5.75, returns 0.75 (for negatives, it returns a negative fraction).

Common Use Cases

• Billing in whole units: Charge only for complete hours or units used.
• Removing time from date-times before grouping or comparing dates.
• Financial reporting where rules require truncating rather than rounding.
• Splitting a value into whole and fractional parts, e.g. hours and minutes from decimal hours.
• Age in completed years: =TRUNC(YEARFRAC(B2, TODAY())).

Common Errors

• Expecting rounding: TRUNC never rounds up. If 2.999 should become 3, use ROUND.
• Negative number surprises: People sometimes expect −2.5 to become −3. That's INT or FLOOR behaviour; TRUNC gives −2.
• Display vs. value confusion: A cell formatted to show two decimals may still hold more. TRUNC changes the stored value; formatting doesn't.
• #VALUE!: The input is non-numeric text.

Tips and Best Practices

• Use TRUNC(A2) rather than INT(A2) to strip times from dates — they behave the same for positive serials, and TRUNC makes the intent clear.
• Use negative places to bucket values (to the nearest 10, 100, 1,000) for grouping.
• Remember that floating-point representation can affect truncation: a value displayed as 0.3 might be stored as 0.29999999999999998, giving 0.29 when truncated to 2 places. Round first to a high precision, e.g. =TRUNC(ROUND(A2, 10), 2), if exactness matters.

Related Functions

INT, ROUND, ROUNDDOWN, ROUNDUP, FLOOR, CEILING, MOD, and TO_DATE.