Two-Way Lookups With INDEX-MATCH-MATCH

Imagine a grid of monthly sales where regions run down the left and months run across the top. You want the number where a chosen region meets a chosen month.

A normal lookup finds a value by searching one direction only. A two-way lookup searches in both directions at once: it finds the right row and the right column, then returns the value sitting at their intersection.

The classic tool for this is INDEX combined with two MATCH calls, often written INDEX-MATCH-MATCH.

INDEX returns a value from a range by its position. The full form is INDEX(array, row_num, column_num).

Give it a block of cells, a row number, and a column number, and it hands back the value at that spot. For example, in a grid starting at B2, asking for row 3 and column 2 returns the value 3 rows down and 2 columns across inside that block.

The key idea: INDEX needs positions, not labels. That is exactly what MATCH provides.