Stocks Comparison
Aon vs Marsh & McLennan Companies: revenue, profit, margins and growth compared
Aon brought in $17.2B of revenue in fiscal 2025, Marsh & McLennan Companies $27B in fiscal 2025. Revenue changed by +9.4% at Aon and +10.3% at Marsh & McLennan Companies on the year before, so Marsh & McLennan Companies grew faster. Aon kept 21.5% of its revenue as net profit, Marsh & McLennan Companies 15.4%. Free cash flow was $3.2B at Aon and $5B at Marsh & McLennan Companies.
Side by side, latest fiscal year
| AON | MRSH | |
|---|---|---|
| Fiscal year ended | FY2025 (December 31, 2025) | FY2025 (December 31, 2025) |
| Revenue | $17.2B | $27B |
| Revenue growth | +9.4% | +10.3% |
| Net income | $3.7B | $4.2B |
| Net margin | 21.5% | 15.4% |
| Free cash flow | $3.2B | $5B |
| Free cash flow margin | 18.7% | 18.5% |
| Earnings per share (diluted) | $17.02 | $8.43 |
| Cash | $1.2B | $2.7B |
| Debt | $15.2B | $19.6B |
| Price to earnings | 16.3 | 20.3 |
| Market value | $59B | $81.7B |
| Dividend yield | 1.05% | 2.00% |
| Rank by revenue in sector | #37 of 444 · Finance | #20 of 444 · Finance |
Over the years
Questions about Aon and Marsh & McLennan Companies
Which is bigger by revenue, Aon or Marsh & McLennan Companies?
Marsh & McLennan Companies is bigger by revenue: $27B in fiscal 2025, against $17.2B for Aon in fiscal 2025.
Which keeps more of its revenue as profit, Aon or Marsh & McLennan Companies?
Aon had a net margin of 21.5% in fiscal 2025; Marsh & McLennan Companies had 15.4% in fiscal 2025.
Which grew revenue faster, Aon or Marsh & McLennan Companies?
In their latest fiscal years revenue changed by +9.4% at Aon and +10.3% at Marsh & McLennan Companies.
Where do these numbers come from?
From the annual reports each company files with the SEC (10-K, or 20-F and 40-F for foreign companies), read from their XBRL data. Margins and growth are simple arithmetic on those figures. Nothing here is a recommendation.