Google Sheets LT Function: Syntax, Examples & Tips

What Is LT?

LT is the function form of the < comparison operator in Google Sheets. It takes two values and returns TRUE if the first value is strictly less than the second, and FALSE otherwise. Writing =LT(A2, B2) gives exactly the same result as writing =A2<B2.

Most people reach for the operator because it is shorter, but the function form has its place. It reads clearly when you are nesting logic, it can be easier to explain to colleagues who are not comfortable with symbols, and it is what Sheets itself uses internally when it describes the operator in help tooltips and error messages.

How LT Relates to the < Operator

Google Sheets maps each comparison operator to a named function:

There is no difference in behaviour between LT and <: same type rules, same blank handling, same results. Pick whichever makes the formula easier to read.

Basic Examples

Below a threshold

=LT(B2, 10)

Returns TRUE when stock in B2 is under 10 units.

Under budget

=LT(C2, D2)

Returns TRUE when spend in C2 is lower than budget in D2.

Before a deadline

=LT(E2, DATE(2026, 12, 31))

Returns TRUE for dates before 31 December 2026.

How Sheets Compares Different Kinds of Values

The comparison functions follow exactly the same rules as their operators, so it helps to know them:

• Numbers are compared numerically. Dates and times are stored as serial numbers, so they compare chronologically.
• Text is compared alphabetically and without regard to case — "apple" and "APPLE" are treated as equal.
• Mixed types do not raise an error. Google's documentation doesn't spell out how text ranks against numbers, so a number stored as text (for example "100" typed with a leading apostrophe or imported from a CSV) can produce a surprising answer.
• Blank cells behave like 0 in a numeric comparison and like an empty string "" in a text comparison.
• Errors propagate: if either argument is an error such as #N/A, the result is that error.

Common Use Cases

• Low-stock alerts: Flag items that need reordering.
• Budget monitoring: Show which cost centres are under budget.
• Deadline tracking: Identify items submitted before a cutoff.
• Quality control: Flag measurements below a tolerance.

Using LT with Arrays

Like the operator, LT works element by element when wrapped in ARRAYFORMULA, which is handy for producing a whole column of TRUE/FALSE flags at once:

=ARRAYFORMULA(LT(B2:B100, C2:C100))

The result can feed straight into FILTER, COUNTIF-style logic via SUMPRODUCT, or conditional formatting.

Common Errors

• Blank cells reported as low: An empty cell counts as 0, so =LT(B2, 10) is TRUE for a blank B2. Guard with AND(B2<>"", LT(B2, 10)).
• Text that looks numeric: A text "5" may not compare as less than 10; convert it with VALUE first.
• Strictness: A value equal to the threshold returns FALSE; use LTE if it should count.

Tips and Best Practices

• LT is strict; for inclusive use LTE.
• LT(a, b) equals GT(b, a).
• For alphabetical tests, =LT(A2, "M") returns TRUE for text starting with A through L (case-insensitive).
• Combine LT with AND, OR and NOT to build multi-part tests, e.g. =AND(LT(A2, B2), C2<>"").
• In conditional formatting custom formulas, either form works; the operator is usually shorter.

Related Functions

EQ, NE, GT, GTE, LTE, ISBETWEEN and IF. For counting or summing based on comparisons across a range, use COUNTIF or SUMIF with an operator criterion such as "<100".