Aon (AON) Cyclically Adjusted PB Ratio: (As of Sep. 20, 2026)

Author: Vera Yuan Vera Yuan
Vera Yuan
Vera Yuan
Director of Data and Quant Analytics at GuruFocus
Focused on building reliable datasets, financial models, and research tools for value-minded investors. Committed to turning complex data into practical guidance for value-investing and long-term wealth.
Reviewed by: Charlie Tian Charlie Tian
Charlie Tian
Charlie Tian
Founder & CEO of GuruFocus
Dr. Charlie Tian is the founder and CEO of GuruFocus.com, a leading global investment research platform established in 2004. With a Ph.D. in physics, Dr. Tian transitioned from science to finance, applying a data-driven, disciplined approach to value investing.

AON Aon PLC AON
94 GF Score
Price $295.64
GF Value $393.79
Valuation Modestly Undervalued
! 1 Warning Sign
View Full Analysis

What is Aon Cyclically Adjusted PB Ratio?

Shiller PE for Stocks: The True Measure of Stock Valuation


Aon  (NYSE:AON) Cyclically Adjusted PB Ratio Explanation

Compared with the regular PB Ratio, which works poorly for cyclical businesses, the Cyclically Adjusted PB Ratio smoothed out the fluctuations of book value during business cycles. Therefore it is more accurate in reflecting the valuation of the company.

If a company has consistent business performance, the Cyclically Adjusted PB Ratio should give similar results to regular PB Ratio.


Aon Cyclically Adjusted PB Ratio Related Terms


Aon Cyclically Adjusted PB Ratio Historical Data

* Premium members only.

The historical data trend for Aon's Cyclically Adjusted PB Ratio can be seen below:

* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD.
* For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.

Aon Cyclically Adjusted PB Ratio Chart

Aon Annual Data
Trend Dec16 Dec17 Dec18 Dec19 Dec20 Dec21 Dec22 Dec23 Dec24 Dec25
Cyclically Adjusted PB Ratio
Get a 7-Day Free Trial Premium Member Only Premium Member Only 14.72 15.81 17.97 21.78 19.02

Aon Quarterly Data
Sep21 Dec21 Mar22 Jun22 Sep22 Dec22 Mar23 Jun23 Sep23 Dec23 Mar24 Jun24 Sep24 Dec24 Mar25 Jun25 Sep25 Dec25 Mar26 Jun26
Cyclically Adjusted PB Ratio Get a 7-Day Free Trial Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only Premium Member Only 19.25 18.91 18.19 15.95 15.91

AON vs AJG, MRSH, WTW: Cyclically Adjusted PB Ratio Comparison

For the Insurance Brokers subindustry, Aon's Cyclically Adjusted PB Ratio, along with its competitors' market caps and Cyclically Adjusted PB Ratio data, can be viewed below:

* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.


Aon Cyclically Adjusted PB Ratio vs Insurance Industry

For the Insurance industry and Financial Services sector, Aon's Cyclically Adjusted PB Ratio distribution charts can be found below:

* The bar in red indicates where Aon's Cyclically Adjusted PB Ratio falls into.


AON
94GF Score
Aon PLC AON
Cyclically Adjusted PB Ratio is just one metric. See GF Score™, valuation, warning signs, and more.
View Full Analysis

Aon Cyclically Adjusted PB Ratio Calculation

Like the Shiller PE Ratio, the Cyclically Adjusted PB Ratio takes the Book Value per Share from the past 10 years, adjusts it for inflation, and then calculates the average. This average is then used for the P/B calculation. Because it considers this 10-year average, it's often referred to as the CAPB Ratio.

The Shiller PE Ratio was first used by professor Robert Shiller to measure the valuation of the overall market. The similar calculation is applied by GuruFocus to calculate the Cyclically Adjusted PB Ratio.

Aon's Cyclically Adjusted Book per Share for the quarter that ended in Jun. 2026 is calculated as:

For example, Aon's adjusted Book Value per Share data for the three months ended in Jun. 2026 was:

Adj_Book=Book Value per Share/CPI of Jun. 2026 (Change)*Current CPI (Jun. 2026)
=45.802/128.6700*128.6700
=45.802

Current CPI (Jun. 2026) = 128.6700.

Aon Quarterly Data

Book Value per Share CPI Adj_Book
201609 20.850 100.274 26.754
201612 21.115 99.676 27.257
201703 22.169 100.374 28.419
201706 21.717 100.673 27.757
201709 20.921 100.474 26.792
201712 18.772 100.075 24.136
201803 21.962 100.573 28.097
201806 19.004 101.072 24.193
201809 17.944 101.371 22.776
201812 17.572 100.773 22.437
201903 20.183 101.670 25.543
201906 16.602 102.168 20.908
201909 15.211 102.268 19.138
201912 14.860 102.068 18.733
202003 13.926 102.367 17.504
202006 15.961 101.769 20.180
202009 15.794 101.072 20.107
202012 15.889 101.072 20.228
202103 19.279 102.367 24.233
202106 20.244 103.364 25.200
202109 10.384 104.859 12.742
202112 5.391 106.653 6.504
202203 6.064 109.245 7.142
202206 3.724 112.779 4.249
202209 -3.227 113.504 -3.658
202212 -2.089 115.436 -2.328
202303 0.284 117.609 0.311
202306 0.797 119.662 0.857
202309 -2.420 120.749 -2.579
202312 -3.736 120.749 -3.981
202403 -0.141 120.990 -0.150
202406 28.352 122.318 29.824
202409 30.268 121.594 32.029
202412 29.769 122.439 31.284
202503 33.660 123.405 35.096
202506 37.501 124.492 38.760
202509 38.099 124.810 39.277
202512 44.513 125.770 45.539
202603 46.723 127.830 47.030
202606 45.802 128.670 45.802

Add all the adjusted book value per share together and divide the count will get our Cyclically Adjusted Book per Share.

Please note that we use the CPI data of the country/region where the company is headquartered. If the CPI data for that country/region is not available, then we will use the CPI data of the United States as default.

Is Aon (AON) Overvalued in 2026?

Based on GuruFocus' analysis, Aon stock appears to be undervalued. The current stock price of $295.64 is trading 24.9% below its estimated GF Value™ of $393.79. GuruFocus considers Aon to be Modestly Undervalued.

Key valuation signals for AON:

  • Cyclically Adjusted PB Ratio:
  • GF Value™: $393.79 vs. price of $295.64 (24.9% below fair value)
  • GF Score™: 94/100 with 1 warning sign

No single metric tells the full story. See the AON stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.


Aon Business Description

Address 15 George\'s Quay, Dublin 2, Dublin, IRL, D02 VR98
Aon is a leading global provider of insurance and reinsurance brokerage and human resources solutions. Its operations are tilted toward its brokerage operations. Headquartered in London, Aon has about 60,000 employees and operations in over 120 countries.
94GF Score

Get the complete analysis for AON

Cyclically Adjusted PB Ratio is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.

$295.64
Price
$393.79
GF Value