Transform Every Value with MAP

Excel 365LAMBDA

MAP applies the same calculation to every cell of an array and spills the results — tax on each price, a grade for each score — without dragging a formula down a column. One formula, the whole transformed array.

Quick formula: to add 8% tax to every price in B2:B100:

=MAP(B2:B100, LAMBDA(p, p * 1.08))

For each value p, the LAMBDA returns p * 1.08; MAP spills one result per input cell.

Functions used (tap for the full reference guide):

MAP LAMBDA

The example

MAP turns each price into a tax-included price in one spilled formula.

	A	B
1	Price	+8% tax
2	100	108
3	50	54
4	200	216

The formula

Tax-included prices, spilled:

=MAP(A2:A4, LAMBDA(p, p * 1.08)) // 108, 54, 216

How it works

MAP is “do this to each element”:

The first argument is the array to transform (A2:A4).
The LAMBDA(p, …) receives each element as p and returns its transformed value — p * 1.08.
MAP spills one output per input, in the same shape as the source.
Feed it multiple arrays for element-wise math across columns: MAP(qty, price, LAMBDA(q, p, q*p)).

MAP vs a plain spilled formula. For simple math, =B2:B100*1.08 already spills — you don’t need MAP. Reach for MAP when each element needs logic (an IF, a lookup, a multi-step calculation) wrapped in a LAMBDA.

Try it: interactive demo

Live demo

Pick a transform; MAP applies it to {100, 50, 200}.

Transform each value

Spills:

Variations

Element-wise across two arrays

Multiply quantity by price, row for row:

=MAP(B2:B100, C2:C100, LAMBDA(q, p, q * p))

Per-value logic (grades)

Wrap an IF inside the LAMBDA:

=MAP(B2:B100, LAMBDA(s, IF(s>=60, "Pass", "Fail")))

Per-value lookup

Look each item up:

=MAP(B2:B100, LAMBDA(x, XLOOKUP(x, ids, names)))

Pitfalls & errors

Don’t use MAP for simple math. =B2:B100*1.08 spills natively. MAP is for per-element logic, not arithmetic that already broadcasts.

Array shapes must match when you pass several arrays to MAP — same number of rows and columns, or it errors.

Excel 365 only. LAMBDA-based functions don’t exist before 365; drag a normal formula down there.

Practice workbook

📊

Download the free Transform Every Value with MAP practice workbook

MAP tax, square, grade, and two-array examples (results shown), plus 4 challenges with answers. No sign-up required.

Frequently asked questions

What does the MAP function do in Excel?

MAP applies a LAMBDA to every element of an array and spills the results: =MAP(range, LAMBDA(x, ...)). It's like dragging a formula down, but in one cell. Requires Excel 365.

How do I use MAP across two columns?

Pass both arrays and a two-parameter LAMBDA: =MAP(qty, price, LAMBDA(q, p, q*p)) multiplies them element by element.

When do I need MAP instead of a normal spilled formula?

For simple arithmetic, =range*1.08 already spills. Use MAP when each element needs logic like an IF, a lookup, or a multi-step calculation wrapped in a LAMBDA.

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Function references: MAP · LAMBDA