Adjusted Diluted Shares Calculator

Which share count should you divide your DCF equity value by?

XBRL exposes three different share figures. Each is the right answer to a different question: cover-page CSO is the most current basic count, balance-sheet CSO is older but matches the income statement period, and weighted-average diluted is GAAP-required for EPS but averaged across the entire period — for filers running active buybacks it overstates today's actual share count by millions of shares. This tool combines the most current snapshot with the Treasury Stock Method (TSM) ratio to give the "fully-diluted as of today" number — the conceptually correct denominator for per-share intrinsic value math.

Try one of these — picked to span the range of dilution overhangs you'll see in the wild:

SEC EDGAR

Adjusted (TSM-scaled) shares

The four candidate share counts

XBRL gives you three raw counts plus the derived adjusted number. Each is the right answer to a slightly different question. The colour coding marks which one you should pick for per-share valuation math (green) versus which serve as anchor inputs (grey).

Calculation trail

Step-by-step derivation. Every line cites the exact us-gaap (or dei) concept tag and accession number so you can verify against the original SEC filing.

Market cap by denominator (optional)

Enter a price to see how each share count produces a different market cap. The gap is the dollar magnitude of the denominator-choice decision.

Price per share

Apply this denominator

One-click links pre-fill the EPV and Expectations calculators with the adjusted-shares figure as the diluted-shares input. Both calculators auto-run.

Open in EPV calculator Open in Expectations / reverse-DCF Cross-check on /financials/<ticker>/valuation/

Methodology

Concept tags this tool reads:

dei:EntityCommonStockSharesOutstanding — cover-page CSO. Required by SEC on every 10-K / 10-Q. As-of date is approximately the filing date — typically the most recent basic-share-count snapshot anywhere in the filing.
us-gaap:CommonStockSharesOutstanding — balance-sheet CSO. Period-end snapshot from the balance sheet (as of the fiscal period close). Older than the cover-page version by the filing lag.
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic — basic weighted-average over the reporting period. Used as the denominator in the basic EPS calculation.
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding — diluted weighted-average over the reporting period. TSM-adjusted; used as the GAAP-required denominator in diluted EPS.

Treasury Stock Method (TSM). GAAP requires diluted EPS to assume every in-the-money option, RSU, and convertible gets exercised today, with the proceeds (option strike payments) used to buy back shares at the current market price. The net incremental dilution is then added to basic shares. The net effect is captured in the basic-to-diluted ratio (diluted ÷ basic) on the income statement. We use that ratio to scale the most current basic CSO snapshot, producing "TSM-scaled diluted shares as of today."

Why "current CSO × TSM ratio" instead of "weighted-average diluted": the weighted-avg figure is an average across the reporting period — for filers with an active buyback program (the typical large-cap pattern), shares retired in the second half of the period are weighted into the average even though they're no longer outstanding. The cover-page CSO is point-in-time and current. Combining a current point-in-time count with the TSM ratio gives the cleanest "diluted shares right now" number.

Materiality bands. A TSM uplift below 1% (LULU, KO, BRK-B) means options/RSUs are immaterial and the basic-vs-diluted distinction barely affects per-share math. Above 5% (NVDA, TSLA, AVGO) means the dilution overhang is material and the model needs to use the diluted figure or it'll systematically overstate per-share value.

Edge cases. Multi-class structures (GOOG/GOOGL, BRK-A/B): the share counts include all classes; the per-share value is the same across classes by construction (same equity claim per share unit). When the cover-page CSO comes from an older filing than the latest 10-Q's balance-sheet CSO, the balance-sheet count wins as the "current" anchor. Filers using IFRS, OTC pinks, and pre-XBRL legacy filers won't appear in the SEC ticker map.