The Yield to Maturity (YTM) of a bond is the annualized return an investor will receive if they buy a bond at its current market price and hold it until maturity, assuming the company makes all the required payments, and the investor reinvests the interest payments at the same rate as the overall return.
The YTM measures “what should happen” when an investor buys a bond – but often does not.
In many cases, investors decide to sell bonds early because of changes in the macro environment or the company’s credit profile.
The YTM ignores all these possibilities and assumes that the investor does hold the bond until the official maturity date, at which point, the company repays it in full.
Unlike metrics such as the Current Yield, the Yield to Maturity measures the annualized return over many years.
Unlike metrics such as the Yield to Call or Yield to Worst, the Yield to Maturity assumes NO early repayment.
Learn accounting, 3-statement modeling, valuation/DCF analysis, M&A and merger models, and LBOs and leveraged buyout models with 10+ global case studies.
The Yield to Maturity changes based on the bond’s current market price, its coupon rate, the time until maturity, and the repayment probability – though this probability is assumed to be 100% for healthy companies.
Here’s a simple Excel example for the YTM calculation of a discount bond that trades at $900 vs. a par value of $1,000:
There are several ways to calculate or approximate the Yield to Maturity, which we’ll describe below:
Calculating yield to maturity (YTM) is an essential skill for investors interested in bonds and other fixed-income securities. But what exactly is yield to maturity and how do you calculate it? In this comprehensive guide, I’ll walk through the intuition behind YTM the formula to calculate it, and provide several step-by-step examples.
What is Yield to Maturity?
Yield to maturity (YTM) is a measure of the total annual return you can expect to earn on a bond if you hold it until it matures, It accounts for both the bond’s coupon payments as well as any capital gains or losses from buying the bond below or above par value,
In other words, YTM tells you the overall annual rate of return you can anticipate from a bond investment based on its purchase price, interest payments, and duration until maturity. It allows you to easily compare bonds with different maturities and coupon rates
The higher a bond’s YTM, the more attractive it generally is to investors. However, you must also consider the bond’s risk factors such as credit quality and interest rate sensitivity when assessing potential investments.
Yield to Maturity Formula
The formula to calculate a bond’s YTM is:
Annual Coupon Payments + (Face Value – Purchase Price) / Years to Maturity
(Face Value + Purchase Price) / 2
Let’s break this formula down:
-
Annual Coupon Payments – The annual interest payment on the bond’s face value based on its coupon rate
-
Face Value – The full amount the bond will be worth at maturity, also called par value
-
Purchase Price – The current market price of the bond, which may be above or below par
-
Years to Maturity – The number of years until the bond matures and pays back its face value
-
(Face Value + Purchase Price) / 2 – Calculates the bond’s average value over its remaining life
This may look complicated at first, but becomes very straightforward with an example.
Step-by-Step YTM Calculation
Let’s walk through calculating YTM on a simple bond investment:
- Face Value: $1,000
- Coupon Rate: 5%
- Years to Maturity: 5
- Purchase Price: $950
Step 1) Determine Annual Coupon Payment
- $1,000 Face Value x 5% Coupon Rate = $50 Annual Coupon
Step 2) Calculate Gain/Loss on Bond
- $1,000 Face Value – $950 Purchase Price = $50 Gain
Step 3) Divide Gain by Years to Maturity
- $50 Gain / 5 Years = $10 Annual Gain
Step 4) Find Average Bond Value
- ($1,000 Face Value + $950 Purchase Price) / 2 = $975 Average Value
Step 5) Calculate YTM
- $50 Annual Coupon + $10 Annual Gain
- $975 Average Value = 0.061 or 6.1% Yield to Maturity
So for this bond, with 5 years until maturity, an investor can expect an annual return of 6.1% on their investment based on the purchase price of $950.
The YTM here is higher than the 5% coupon rate because the bond was purchased at a discount to face value. The capital gain from the discount increases the total return above the coupon payments alone.
Yield to Maturity Examples
Now let’s run through a few more examples to solidify the intuition behind YTM and how to calculate it.
Example 1) Bond Trading at Par
- Face Value: $1,000
- Coupon: 6%
- Maturity: 10 years
- Price: $1,000
- 6% of $1,000 = $60 Annual Coupon
- No Capital Gain/Loss at Par
- $1,000 Average Value
- $60 / $1,000 = 6% YTM
Here the YTM equals the coupon rate because there is no capital gain or loss on the bond purchase. The bond is simply returning 6% annually from its coupon payments.
Example 2) Bond Trading at Discount
- Face Value: $1,000
- Coupon: 4%
- Maturity: 5 years
- Price: $900
- 4% of $1,000 = $40 Annual Coupon
- $1,000 – $900 = $100 Capital Gain
- $100 / 5 years = $20 Annual Gain
- ($1,000 + $900) / 2 = $950 Average Value
- $40 + $20 = $60 Annual Return
- $60 / $950 = 6.3% YTM
Purchased below face value, this bond has a higher YTM due to the embedded capital gain. The total return combines the 4% coupon payment and 6.3% annual gain from the discount purchase price.
Example 3) Bond Trading at Premium
- Face Value: $1,000
- Coupon: 4%
- Maturity: 10 years
- Price: $1,100
- 4% of $1,000 = $40 Annual Coupon
- $1,000 – $1,100 = -$100 Capital Loss
- -$100 / 10 years = -$10 Annual Loss
- ($1,100 + $1,000) / 2 = $1,050 Average Value
- $40 – $10 = $30 Annual Return
- $30 / $1,050 = 2.9% YTM
Here the bond is trading above face value, resulting in an annual capital loss that reduces the total return. The YTM is less than the coupon rate due to this premium pricing. The annual loss partially offsets the 4% coupon payments.
Yield to Maturity Limitations
While an important metric, YTM does have some limitations to consider:
-
Assumes reinvestment of coupons at same rate – This may not be possible as rates fluctuate over the bond term.
-
Ignores taxes – Any taxes paid would reduce the total return.
-
Assumes no early call or default – These events would alter the actual maturity and cash flows.
-
Static metric – YTM will change as market rates and the bond price vary.
-
Approximation only – Computed using iterations and convergence, small rounding errors are possible.
For these reasons, YTM should not be considered a guaranteed return, but rather a general estimate of total bond performance. Investors must account for potential risks not incorporated in the YTM formula.
Being able to accurately calculate yield to maturity is an indispensable skill for fixed-income investors and analysts. YTM provides a straightforward way to evaluate and compare bonds across varying coupon rates, prices, and maturities.
While some complexities exist, the underlying YTM formula is intuitive once you break it down step-by-step. With the examples and guidance provided above, you should now feel confident in your ability to determine the anticipated yield on a wide range of bond investments.
When making investment decisions, use YTM as one input among many to assess a bond’s potential risks and rewards. Consider factors such as interest rate exposure, credit quality, and embedded options alongside the calculated YTM metric. Employed prudently, YTM can be a valuable tool to optimize your fixed income portfolio.
YTM Formula: How to Calculate the Yield to Maturity with the IRR Function
Since the Yield to Maturity represents the annualized return on a bond, you can also use the Internal Rate of Return (IRR) function in Excel to calculate it.
However, this approach takes far more time and effort because you must project the cash flows of the bond, including the initial purchase, the interest payments, and the repayment upon maturity.
You can see our setup below:
Just like how the IRR in an LBO model tells you what a PE firm could earn, annualized, on its equity investment in a company, it’s the same principle here with a single bond.
Applying the IRR function to this stream of cash flows confirms that it’s nearly the same as the output from the YIELD function:
YTM Formula: How to Calculate the Yield to Maturity in Excel
The easiest method, by far, is to use the YIELD function in Excel, which accounts for all the assumptions mentioned above.
We use this YIELD function in the screenshot shown above, and you can see it directly in the Excel download available on this page.
The assumptions here are as follows:
Bond Price: $900 (vs. par value of $1,000, so it’s trading at a 10% discount)
Coupon Rate: 5% (so, interest payments will be $1,000 * 5% = $50 per year)
Settlement Date (Purchase Date): December 31, 2024
Maturity Date: December 31, 2029 (5-year holding period)
The output is as follows:
The Excel function is:
=YIELD (Settlement Date, Maturity Date, Coupon Rate, Bond Price % Par Value out of Number 100, 100, Coupon Frequency)
The intuition here is that this 10% discount gives investors an “extra boost” over the 5% coupon rate.
Since they hold the bond for 5 years, this 10% discount is spread out over 5 years, and since 10% / 5 = 2%, the annualized return is ~2% higher than 5% (it’s actually closer to ~2.5% higher due to compounding).