Syntax
BYROW(array, lambda)
| Parameter | Description |
|---|---|
| array | Parameter of the BYROW function. |
| lambda | Parameter of the BYROW function. |
Examples
Sum each row
Formula
=BYROW(A1:D10, LAMBDA(row, SUM(row)))
Returns a 10-row column where each value is the sum of the corresponding row in A1:D10. Row 1 result = A1+B1+C1+D1.
Max minus min per row
Formula
=BYROW(B2:F20, LAMBDA(r, MAX(r)-MIN(r)))
Returns the range (spread) of each row — the difference between the largest and smallest value in that row.
Count non-blank cells per row
Formula
=BYROW(A1:E50, LAMBDA(r, COUNTA(r)))
Returns how many non-empty cells are in each row. Useful for checking data completeness across multiple columns.
Common Errors
#VALUE!
The LAMBDA doesn't accept exactly 1 parameter, or it returns more than one value (BYROW expects a single result per row).
#CALC!
The LAMBDA produces an error for one or more rows.
Tips
LAMBDA must return a single value
Your LAMBDA function must reduce each row to one value (a number, text, etc.). If it returns an array, you get a #VALUE! error.
BYROW vs BYCOL
BYROW iterates over rows and returns a column; BYCOL iterates over columns and returns a row. Choose based on the axis of aggregation.
Complex per-row logic
Use BYROW for logic that considers multiple columns together: =BYROW(data, LAMBDA(r, IF(INDEX(r,1)>INDEX(r,2), "Over", "Under"))) compares columns within each row.
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