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Lesson 5 of 6 11–14% of the exam

Diluted EPS: if-converted and treasury stock methods

Diluted earnings per share (EPS) assumes potential shares are issued whenever that lowers EPS. For convertibles, add back the preferred dividends or after-tax interest and add the new shares. For options, the treasury stock method adds only the net new shares: N × (average price − exercise price) ÷ average price.

8 min cram, 32 min full read. Based on the 2027 CFA® Program Level I curriculum, Financial Statement Analysis, Learning Module 2. Also part of the 2026 curriculum, so it applies to the November 2026 exam too.

Tailor this to you: take the self-assessment

Before this: Basic EPS and the weighted average number of shares

On the exam

  • Describe how earnings per share is calculated and calculate and interpret a company’s basic and diluted earnings per share for companies with simple and complex capital structures including those with antidilutive securities

Calculate and interpret diluted EPS for a complex capital structure and identify antidilutive securities. The single most likely calculation item in Financial Statement Analysis.

How deeply to learn each part
Know the idea
Understand it in general. It frames other topics, but you will not calculate with it.
Use it
Understand it well enough to solve a question with it. Recognize when it applies.
Memorize
Learn it by heart. The exam will not give it to you.

You know this one. The full lesson is folded away. The takeaways, formulas and checkpoint below are your quick refresher, and the checkpoint is a fair test of whether you still do.

You tested strong here. The full lesson is folded away. The takeaways, formulas and checkpoint below are your quick refresher, and the checkpoint is a fair test of whether you still know it.

Cram mode: the one-screen version of this lesson. Switch to Full for the explanations, worked examples and interactives.

What is diluted EPS?

Diluted EPS is EPS if every security that could become a common share, and would lower EPS, had been converted or exercised. It is the conservative figure, so it is never above basic EPS.

Diluted EPS Memorize
EPSd=NI−Dp+Dconv+AW+C+ΔSEPS_d = \frac{NI - D_p + D_{conv} + A}{W + C + \Delta S}

Here DpD_p is all preferred dividends, DconvD_{conv} those on convertible preferred being assumed converted, AA the after-tax interest on convertible debt being assumed converted, CC the conversion shares and ΔS\Delta S the net new option shares. Only securities that dilute enter.

How does the if-converted method work?

Memorize

The if-converted method pretends the convertible was converted at the start of the year. The payments you would no longer make go back into the numerator, and the new shares go into the denominator.

  • Convertible preferred stock : add back its preferred dividends, add the conversion shares.
  • Convertible debt : add back the after-tax interest, add the conversion shares. Interest saves tax, so the add-back is interest × (1 − tax rate).
After-tax interest on convertible debt Use it
A=F×c×(1−t)A = F \times c \times (1 - t)
Rearrange itConvertible debt: the after-tax interest to add back
The question asks for
Convertible bonds have a face value of 18,000.00 and a 6.00% coupon. The tax rate is 25.00%. The amount added back to the numerator of diluted EPS is closest to:

18,000.00 × 0.06 × (1 − 0.25) = 810.00

After-tax interest810.00

On your calculator
  1. 18000×0.06×0.75=
  1. 18000ENTER0.06×0.75×

ENTER enter (on the HP, puts the number on the stack)

How does the treasury stock method work?

Memorize

The treasury stock method handles options and warrants . Assume they are exercised, then assume the exercise cash is used to repurchase shares at the average market price. Only the net new shares dilute. The numerator does not change.

Treasury stock method: incremental shares Memorize
ΔS=N−N×KPavg=N×Pavg−KPavg\Delta S = N - \frac{N \times K}{P_{avg}} = N \times \frac{P_{avg} - K}{P_{avg}}

The options count only when they are in the money (K below the average price). Under International Financial Reporting Standards (IFRS) the shortfall is described as shares issued for no consideration, which gives the same number.

Rearrange itTreasury stock method: incremental shares from options
The question asks for
A company has 400 thousand options with an exercise price of 30.00. The average market price during the year was 48.00. Under the treasury stock method, the incremental shares, in thousands, are closest to:

400 × (48.00 − 30.00) ÷ 48.00 = 150

Incremental shares (thousands)150

On your calculator
  1. 48−30=×400÷48=
  1. 48ENTER30−400×48÷

ENTER enter (on the HP, puts the number on the stack)

Exam tip The year-end price is a decoy. Every treasury stock question wants the average price for the period.

What does a full calculation look like?

Compute basic EPS, test each security, include only those that dilute, then divide.

Rearrange itDiluted EPS: add back, add shares, then divide
The question asks for
Income to common shareholders is 11,000.00 on 6000 thousand weighted shares. Convertible securities would add back 810.00 and create 600 thousand shares, and options add 150 thousand incremental shares. All are dilutive. Diluted EPS is closest to:

(11,000.00 + 810.00) ÷ (6000 + 600 + 150) = 1.75

Diluted EPS1.75

On your calculator
  1. 11000+810=STO1
  2. 6000+600+150=STO2
  3. RCL1÷RCL2=

STO store · RCL recall a stored number

  1. 11000ENTER810+6000ENTER600+150+÷

ENTER enter (on the HP, puts the number on the stack)

InteractiveDiluted EPS: only the securities that cut EPS go in

Try this 0 of 3

  • Lower the average share price until the options stop counting
  • Make the convertible preferred dilutive
  • Make the convertible bonds antidilutive
3.20 per new share · antidilutive, out
1.35 per new share · dilutive, in
150k new shares, no add-back · dilutive, in
Basic EPS1.83
Diluted EPS1.75
Shares in the diluted count (k)6,750
Show working

Basic EPS = (12,000 − 1,000) ÷ 6,000 = 1.83

Bonds: add back 18,000 × 0.06 × (1 − 0.25) = 810.0; per new share 810.0 ÷ 600 = 1.35

Preferred: add back 800; per new share 800 ÷ 250 = 3.20

Options: 400 − 400 × 30 ÷ 48 = 150k new shares

Order by add-back per share, most dilutive first: options and warrants (0) in, convertible bonds (1.35) in, convertible preferred (3.20) out.

Diluted EPS = (11,000 + 810.0) ÷ (6,000 + 750) = 11,810.0 ÷ 6750 = 1.75. Left out: convertible preferred.

Diluted EPS on your calculator
  1. 11000+810=÷(6000+750)=1.7496
  1. 11000ENTER810+6000ENTER750+÷1.7496

ENTER enter (on the HP, puts the number on the stack)

Option shares on your calculator
  1. 400−(400×30÷48)=150
  1. 400ENTER400ENTER30×48÷−150

ENTER enter (on the HP, puts the number on the stack)

Only securities that cut EPS go in.

How do you spot an antidilutive security?

Antidilutive securities are those that would raise EPS if included, so leave them out. For a convertible, divide its add-back by its new shares and compare with basic EPS. Above basic EPS means antidilutive.

Dilution test (add-back per new share) Use it
q=A or DconvC,include only if q<basic EPSq = \frac{A \text{ or } D_{conv}}{C}, \quad \text{include only if } q < \text{basic EPS}
Potentially dilutive securities and their methods
Complex capital structurediluted EPS assumes the dilutive ones are issued
  • If-converted method Memorize convertibles
    • Convertible preferred add back dividends, add shares
    • Convertible debt add back after-tax interest, add shares
  • Treasury stock method Memorize options and warrants
    • In the money (K below average price) net new shares, no numerator change
    • Out of the money (K above average price) antidilutive, excluded
Include it or leave it out?
Does including the security raise EPS?
  • No, EPS falls: dilutive Memorize include it
  • Yes, EPS rises: antidilutive Memorize exclude it
    • Convertibles add-back per new share above basic EPS
    • Options exercise price above average price

Options are antidilutive when K is above the average price. Because every antidilutive security is left out, diluted EPS can never exceed basic EPS.

Go deeper Several convertibles: rank them

With more than one convertible, the strict procedure ranks securities from the lowest add-back per new share to the highest and adds them in that order, stopping when EPS stops falling. At Level I you can usually test each against basic EPS on its own. The ranked procedure matters when including a security changes the EPS against which the next one is tested.

Go deeper Securities issued or converted during the year

A security outstanding all year is treated as converted at the start of the year. One issued during the year is included from its issue date, weighted by the fraction of the year. One converted during the year has its effect for the part before conversion in the numerator and denominator, while the actual shares are already in the weighted average count after conversion.

Go deeper Why the average price and not the year-end price

Diluted EPS is an earnings-for-the-period figure. The share price the options would have been tested against over the period, and the price at which the company would have repurchased shares through the period, is the average. A year-end price would reflect a single day, so a rally in December would overstate dilution for the whole year.

Memorize this

MemorizeWhat each security does to the formula

SecurityNumeratorDenominator
Convertible preferred+ its preferred dividends+ conversion shares
Convertible debt+ interest × (1 − tax rate)+ conversion shares
Options and warrantsNo change+ N × (P_avg − K) ÷ P_avg, if K < P_avg

Memory hook Convertibles: add back what you would stop paying, add the shares. Options: shares you get minus shares you buy back with the cash, at the average price.

Know it cold Include a security only if it lowers EPS. Diluted EPS is never above basic EPS.

MemorizeThe dilution test

SecurityDilutive (include) ifAntidilutive (exclude) if
Convertible preferredDividends ÷ new shares < basic EPSDividends ÷ new shares > basic EPS
Convertible debtAfter-tax interest ÷ new shares < basic EPSAfter-tax interest ÷ new shares > basic EPS
Options and warrantsExercise price < average priceExercise price > average price

Memory hook Compare the "price" of each new share (what you add back per share) with what an existing share earns. Dearer than basic EPS: leave it out.

Know it cold Use the average market price, not the year-end price, in the treasury stock method.

Potentially dilutive securities and their methods
Complex capital structurediluted EPS assumes the dilutive ones are issued
  • If-converted method Memorize convertibles
    • Convertible preferred add back dividends, add shares
    • Convertible debt add back after-tax interest, add shares
  • Treasury stock method Memorize options and warrants
    • In the money (K below average price) net new shares, no numerator change
    • Out of the money (K above average price) antidilutive, excluded
Include it or leave it out?
Does including the security raise EPS?
  • No, EPS falls: dilutive Memorize include it
  • Yes, EPS rises: antidilutive Memorize exclude it
    • Convertibles add-back per new share above basic EPS
    • Options exercise price above average price
Diluted EPS Memorize
EPSd=NI−Dp+Dconv+AW+C+ΔSEPS_d = \frac{NI - D_p + D_{conv} + A}{W + C + \Delta S}
Quick example

Income to common 8,000 on 2,000 shares (basic 4.00). Convertible bonds add back 210 of after-tax interest and 100 shares. 8,210 ÷ 2,100 = 3.91.

On your calculator
  1. 2000+100=STO1
  2. 8000+210=÷RCL1= 3.9095

STO store · RCL recall a stored number

  1. 8000ENTER210+2000ENTER100+÷ 3.9095

ENTER enter (on the HP, puts the number on the stack)

After-tax interest on convertible debt Use it
A=F×c×(1−t)A = F \times c \times (1 - t)
Quick example

Bonds with face value 12,000 and a 5% coupon, tax rate 20%. 12,000 × 0.05 × 0.80 = 480 added back.

On your calculator
  1. 12000×0.05×0.8= 480
  1. 12000ENTER0.05×0.8× 480

ENTER enter (on the HP, puts the number on the stack)

Treasury stock method: incremental shares Memorize
ΔS=N−N×KPavg=N×Pavg−KPavg\Delta S = N - \frac{N \times K}{P_{avg}} = N \times \frac{P_{avg} - K}{P_{avg}}
Quick example

50,000 options, exercise price 18, average price 24. 50,000 × (24 − 18) ÷ 24 = 12,500 new shares.

On your calculator
  1. 24−18=×50000÷24= 12500
  1. 24ENTER18−50000×24÷ 12500

ENTER enter (on the HP, puts the number on the stack)

Dilution test (add-back per new share) Use it
q=A or DconvC,include only if q<basic EPSq = \frac{A \text{ or } D_{conv}}{C}, \quad \text{include only if } q < \text{basic EPS}
Quick example

Basic EPS 2.40. A convertible would add back 380 and create 100 shares: 380 ÷ 100 = 3.80, above 2.40, so it is antidilutive and left out.

On your calculator
  1. 380÷100= 3.8
  1. 380ENTER100÷ 3.8

ENTER enter (on the HP, puts the number on the stack)

How it is asked

  1. Treasury stock method increment

    120,000 options, exercise price 36, average price 45, year-end price 60. Incremental shares?

    120,000 × (45 − 36) ÷ 45 = 24,000. Year-end price gives 48,000 (trap); ignoring the buyback gives 120,000.

  2. Convertible bonds

    Net income 6,300, shares 1,800, bonds face 9,000 at 6% convert into 450 shares, tax 25%. Diluted EPS?

    (6,300 + 9,000 × 0.06 × 0.75) ÷ (1,800 + 450) = 2.98. Pre-tax interest (3.04) and no add-back (2.80) are the traps.

  3. Antidilutive

    Options with an exercise price above the average market price. Treatment?

    Excluded from diluted EPS: including them would raise EPS or add nothing.

  4. Convertible preferred

    Do you subtract the convertible preferred dividends and also add its shares?

    No. If converted, the dividends are not paid, so they stay in the numerator (added back) and the shares go in the denominator.

Exam traps

  • Using the year-end share price in the treasury stock method. Use the average price for the period.
  • Adding back pre-tax interest on convertible debt. Add back interest × (1 − tax rate).
  • Including an antidilutive security. If it raises EPS, leave it out.
  • Subtracting convertible preferred dividends and also adding its shares. Dividends are added back.

Checkpoint

3 exam-style questions. About 90 seconds each.

  1. 1A company has 200,000 options outstanding with an exercise price of GBP 25. The average share price for the year is GBP 40 and the year-end price is GBP 50. The incremental shares under the treasury stock method are closest to:

  2. 2Net income is USD 3,000k, weighted average shares are 1,000k and there is no preferred stock. Convertible bonds with a face value of USD 5,000k and a 4% coupon convert into 200k shares. The tax rate is 30%. Diluted EPS is closest to:

  3. 3Stock options with an exercise price above the average market price during the period are:

Key takeaways

  • If-converted: add back preferred dividends or after-tax interest, and add the conversion shares.
  • Treasury stock method: incremental shares = N × (P_avg − K) ÷ P_avg, with no numerator change.
  • Exclude anything that raises EPS. Diluted EPS is never higher than basic EPS.
Diluted EPS Memorize
EPSd=NI−Dp+Dconv+AW+C+ΔSEPS_d = \frac{NI - D_p + D_{conv} + A}{W + C + \Delta S}
Quick example

Income to common 8,000 on 2,000 shares (basic 4.00). Convertible bonds add back 210 of after-tax interest and 100 shares. 8,210 ÷ 2,100 = 3.91.

On your calculator
  1. 2000+100=STO1
  2. 8000+210=÷RCL1= 3.9095

STO store · RCL recall a stored number

  1. 8000ENTER210+2000ENTER100+÷ 3.9095

ENTER enter (on the HP, puts the number on the stack)

After-tax interest on convertible debt Use it
A=F×c×(1−t)A = F \times c \times (1 - t)
Quick example

Bonds with face value 12,000 and a 5% coupon, tax rate 20%. 12,000 × 0.05 × 0.80 = 480 added back.

On your calculator
  1. 12000×0.05×0.8= 480
  1. 12000ENTER0.05×0.8× 480

ENTER enter (on the HP, puts the number on the stack)

Treasury stock method: incremental shares Memorize
ΔS=N−N×KPavg=N×Pavg−KPavg\Delta S = N - \frac{N \times K}{P_{avg}} = N \times \frac{P_{avg} - K}{P_{avg}}
Quick example

50,000 options, exercise price 18, average price 24. 50,000 × (24 − 18) ÷ 24 = 12,500 new shares.

On your calculator
  1. 24−18=×50000÷24= 12500
  1. 24ENTER18−50000×24÷ 12500

ENTER enter (on the HP, puts the number on the stack)

Dilution test (add-back per new share) Use it
q=A or DconvC,include only if q<basic EPSq = \frac{A \text{ or } D_{conv}}{C}, \quad \text{include only if } q < \text{basic EPS}
Quick example

Basic EPS 2.40. A convertible would add back 380 and create 100 shares: 380 ÷ 100 = 3.80, above 2.40, so it is antidilutive and left out.

On your calculator
  1. 380÷100= 3.8
  1. 380ENTER100÷ 3.8

ENTER enter (on the HP, puts the number on the stack)

All Financial Statement Analysis formulas, every lesson

Practice exam-style questions on Analyzing Income Statements

Questions about this lesson?

Where this comes back

Questions candidates ask

How do you calculate diluted EPS with convertible bonds?

Add the after-tax interest, interest × (1 − tax rate), to the numerator and the conversion shares to the denominator. Include the bonds only if the add-back per new share is below basic EPS. Net income 6,300, 1,800 shares and bonds adding 405 and 450 shares give 6,705 ÷ 2,250 = 2.98.

What is the treasury stock method?

It assumes in-the-money options are exercised and the cash received is used to buy back shares at the average market price. The net new shares are N × (average price − exercise price) ÷ average price. The numerator does not change.

What does antidilutive mean?

A security is antidilutive if including it would raise EPS (or lower a loss), for example a convertible whose add-back per new share exceeds basic EPS, or options with an exercise price above the average price. Both IFRS and US GAAP (generally accepted accounting principles) exclude them from diluted EPS.

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  1. Revenue recognition: the five-step model
  2. Expense recognition: capitalizing vs expensing
  3. Non-recurring items, discontinued operations and accounting changes
  4. Basic EPS and the weighted average number of shares
  5. Diluted EPS: if-converted and treasury stock methods
  6. Common-size income statements and margin ratios

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