How to Use the LET Function in Excel 365 (Step-by-Step with Examples)

Jun 25, 2025

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The LET function is one of the powerful new additions in Excel 365, designed to make complex formulas easier to read, write, and optimize.

🧠 What is the `LET` Function in Excel?

The LET function allows you to:

Define variables within a formula
Assign values to those variables
Use the variables multiple times without repeating the calculation

This makes formulas cleaner, faster, and more efficient—especially when repeating the same expressions.

🧪 Syntax of the `LET` Function

LET(name1, name_value1, [name2, name_value2, …], calculation)

name1, name2: Variable names (your choice)
name_value1, name_value2: The value or expression assigned to the variable
calculation: The final expression that uses those variables

✅ Benefits of Using `LET`:

Improves readability of complex formulas
Reduces redundancy (no need to repeat the same expression)
Enhances performance (calculates repeated expressions once)

🔍 3 Practical Examples of LET in Excel 365

🔸 Example 1: Simplify a Repeated Calculation

📍 Task:

Calculate total profit using Revenue - Cost, but both are used multiple times in the formula.

🔽 Without `LET`:

=(A2*B2 - C2) + (A2*B2 - C2)*0.1

✅ With `LET`:

=LET(
    Revenue, A2*B2,
    Profit, Revenue - C2,
    Profit + Profit*0.1
)

✔️ This is more readable and avoids repeating A2*B2.

🔸 Example 2: Average of Adjusted Scores

📍 Task:

Subtract a baseline (e.g., 5) from each of three values and then average the results.

✅ With `LET`:

=LET(
    x, A2-5,
    y, B2-5,
    z, C2-5,
    AVERAGE(x, y, z)
)

This makes it clear what is being subtracted and from where.

🔸 Example 3: Nested Logical Check

📍 Task:

If a score is greater than 40, calculate bonus as 10% of it. If it’s less than or equal to 40, no bonus.

✅ With `LET`:

=LET(
    score, A2,
    bonus, score*0.1,
    IF(score>40, bonus, 0)
)

🧠 You can now reuse score and bonus in the formula cleanly.

📘 Real-Life Use Cases

Financial modeling (e.g., tax formulas, profit sharing)
Academic scoring systems
Inventory management with dynamic thresholds
Any case where a formula becomes long or repeats similar calculations

🎓 Learn More Excel 365 Features Like LET

Mastering functions like LET can help you write smarter, faster, and more powerful Excel models. For full Excel training with real-world applications: