LET Function in Excel: Name Parts of a Formula (with Examples)

LET assigns names to values inside one formula. Instead of repeating a long calculation, define it once, refer to its name, and put the final result last. The free workbook uses basePrice, discountAmt, and shipping to calculate a line total of $280.20.

Download the free LET quote calculator workbook (.xlsx)

Quick answer: How to use LET in Excel

The syntax is =LET(name1,value1,calculation). Add more name/value pairs before the final calculation when you need them. For example, =LET(x,5,x+1) returns 6. Names created by LET exist only inside that formula; they do not create workbook-level names.

Microsoft lists LET for Excel for Microsoft 365, Excel 2024, and Excel 2021, including the Mac editions. Check the version before sharing a workbook with someone using an older Excel release.

Step 1: Start with the formula you already understand

Open the workbook’s Quote sheet. Row 5 is the desk lamp example: 8 units at $34.50 each, a 5% discount, and $18.00 shipping. Without LET, the line total is:

=ROUND(B5*C5-B5*C5*D5+E5,2)

The price before discount is B5*C5, or $276.00. The discount is that amount times D5, or $13.80. Add $18.00 shipping and round to cents: ROUND(276-13.8+18,2) returns $280.20. The formula is correct, but the base-price calculation appears twice.

Step 2: Name the intermediate calculations

In F5, replace the previous formula with this LET version:

=LET(basePrice,B5*C5,discountAmt,basePrice*D5,ROUND(basePrice-discountAmt+E5,2))

Read the arguments in order:

1. basePrice receives B5*C5, which is $276.00.
2. discountAmt receives basePrice*D5, which is $13.80.
3. The final argument subtracts the discount, adds shipping from E5, and rounds to two decimal places.

The final argument is required: it tells Excel what to return. Names are local to this formula, so a separate formula that needs basePrice must define it again. The workbook’s How It Works sheet shows the same first-row values and their calculations.

LET is especially useful when the same expression appears more than once or when a nested formula is hard to audit. For a lookup that needs a readable fallback, see the XLOOKUP examples in Excel. For a formula that returns matching rows, continue with the FILTER function guide.

Step 3: Fill the formula down the quote

1. Select F5, then copy or drag the fill handle through F8.
2. Each row should use that row’s units, unit price, discount, and shipping.
3. Compare each result in column F with the check formula in column G.

The remaining line totals are $429.96 for the monitor arm, $311.40 for the cable hub, and $483.14 for the office chair. The formulas use relative references, so filling down changes row 5 references to row 6, row 7, and row 8.

If Excel shows #NAME?, check that each LET name is spelled the same way where it is used. A name cannot look like a cell address such as A1. If Excel rejects commas between arguments, use the list separator configured for your regional settings, often semicolons.

Step 4: Use LET for a readable review rule

The Quote sheet totals the four line amounts in B14 and keeps the review threshold in the blue input cell E11. In B15, this formula names those two values before checking whether the quote meets the threshold:

=LET(quoteTotal,B14,threshold,E11,IF(quoteTotal>=threshold,"Review quote","Standard quote"))

At a $1,500 threshold, the quote total of $1,504.70 returns Review quote. Change E11 to $1,600 and B15 changes to Standard quote. This is a simple example of naming values that makes the condition easier to read. For more decision formulas, see how to combine IF with AND and OR in Excel.

Common LET formula problems

When you create a long model formula, use LET for meaningful intermediate results and keep the final calculation explicit. Then change a key input, compare the result to an independent check, and inspect the formula if the two no longer agree. Excel’s error-checking rules can help you review the rest of the workbook.

Frequently asked questions

The workbook finishes with a $1,504.70 quote total and an independent check for every line. Change a discount or threshold, recalculate, and confirm the named formula still agrees with the check column.