How to Use the RATE Function in Excel

The RATE function allows you to calculate the interest rate of a loan based on known inputs like payment amount, loan term, and total loan value. In this lesson, you’ll learn how the function works and see how it’s used to evaluate financing options for HVAC customers, helping you understand how changes in rate, term, or payment impact affordability and total cost.

Download the Excel file used in this tutorial:

The RATE Function

1. Gather the financing inputs

Start with the key loan details already available in the worksheet:

  • Loan term
  • Monthly payment
  • Loan amount
  • Any optional future value assumption

In the video, the loan term is already expressed in months, which makes the setup easier for the RATE function.

2. Use the RATE function to solve for the interest rate

Enter the RATE function using the financing inputs:

  • Number of periods
  • Monthly payment
  • Present value, which is the loan amount
  • Future value, assumed to be zero in the example

This returns the periodic interest rate, not the full annual rate.

3. Interpret the first result correctly

After pressing Enter, Excel returns a small percentage value.

  • That initial result is the monthly interest rate
  • It is not the annual percentage rate yet
  • This is why the number looks lower than expected at first glance

4. Convert the monthly rate into an annual rate

To make the result easier to interpret for financing comparisons:

  • Multiply the monthly rate by 12
  • Format the result as a percentage
  • Copy the calculation down if you are comparing multiple financing offers

This gives you the annualized rate for each option in the table.

5. Review multiple financing options side by side

Once the annual rate is calculated:

  • Scan down the column to compare lender offers
  • Identify which options have higher or lower effective rates
  • Use that comparison to evaluate whether a financing plan is competitive

This is especially useful when the rate is not clearly provided and you need to back into it from the loan terms.

6. Tie RATE back to the PMT function

In the video, the RATE function is paired with the PMT function to show how the financing pieces connect.

  • RATE helps solve for the interest rate when you already know payment, term, and loan amount
  • PMT helps solve for the monthly payment when you already know the rate, term, and loan amount

Using both functions together makes it easier to test financing scenarios from different angles.

7. Adjust financing assumptions to test affordability

After finding the rate, the next step is scenario testing.

The video shows how you can change variables such as:

  • Interest rate
  • Loan term
  • Monthly payment target

This helps you evaluate questions like:

  • What happens if the rate drops?
  • What happens if the term increases from five years to six years?
  • What payment becomes possible if financing terms improve?

8. Use the function to understand financing tradeoffs

The value of RATE is not just finding a percentage. It is understanding how financing terms work together.

By combining RATE with PMT and other financial functions, you can explore:

  • Lower rates and their impact on payment
  • Longer terms and their impact on affordability
  • Total financing structure options for a customer

This is what makes the function useful in real decision-making, not just calculation.

9. Use RATE when the lender does not clearly show the true rate

The video emphasizes that many financing offers already show the interest rate, but RATE is still useful because it lets you:

  • Verify financing terms
  • Reverse-engineer a loan offer
  • Compare competing options on equal footing

That makes it a practical tool for evaluating financing plans in Excel.

10. Remember that RATE is an iterative function

Unlike some other financial functions, RATE does not come from a simple manual equation in the worksheet.

Excel solves it iteratively behind the scenes, which is why the video does not show a standard formula breakdown.

The important takeaway is simply this:

  • Use RATE to calculate the interest rate from known loan terms

Use PMT alongside it to test how payment changes when financing assumptions change

The RATE Function in Excel

Q1. What does the RATE function do in Excel?
The RATE function calculates the interest rate of a loan or investment based on inputs like number of periods, payment amount, and present value. It helps you determine the true cost of financing.

Q2. Why is the RATE function important for financial analysis?
It allows you to evaluate whether a financing offer is competitive. Instead of just looking at monthly payments, you can calculate the actual interest rate and compare different loan options more accurately.

Q3. Why isn’t there a simple formula behind the RATE function?
The RATE function uses an iterative method (called the Newton-Raphson method) to solve complex financial equations. This means Excel calculates the rate behind the scenes without requiring you to manually apply a formula.

Q4. Why does the result sometimes look like a small percentage?
Excel typically returns the periodic rate (for example, monthly). To get the annual rate, you need to multiply the result by the number of periods in a year (usually 12).

Q5. How is the RATE function connected to other financial functions?
The RATE function works closely with functions like PMT (payment) and PV (present value). Together, they allow you to analyze loans from different angles and adjust variables like term, payment, or rate.

Q6. When should I use the RATE function in real scenarios?
Use it when you want to compare financing offers, validate lender terms, or understand how loan conditions affect monthly payments and total interest paid over time.

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