Free Float (Stock Market) Calculator
Work out the free-float share count, free-float percentage, and free-float market cap used by S&P, MSCI, and FTSE to weight index constituents.
Free float
70%
- Free float shares
- 70,000,000
- Restricted shares
- 30,000,000
- Shares outstanding
- 100,000,000
Free float is the portion of a company's shares available to the public — total shares outstanding minus insider, strategic, government, and other locked-in holdings. Major index providers (S&P, MSCI, FTSE) weight constituents by free-float market cap, not total market cap, so that index weights reflect only the truly investable float. Typical bands: mature blue chips 70–95% free float; family- or founder-controlled companies 20–50%; recent IPOs often below 20% until lock-ups expire. Very low free float (<15%) can trigger index exclusion and typically increases share-price volatility from thin trading.
How to use this calculator
Enter total shares outstanding and the number of restricted shares — insider holdings, strategic stakes (holding companies, other listed firms), government or sovereign-fund holdings, employee-lock-up shares, and any other blocks not available for public trading. Optionally add the current share price to also compute free-float market cap and total market cap. Restricted-share breakdowns are disclosed in the annual report ("major shareholders" section) and on data terminals as "closely held shares".
How the calculation works
Free float = shares outstanding − restricted shares. Free-float % = free float / shares outstanding. Index providers use free-float market cap (free-float shares × price) rather than total market cap when weighting constituents, so that index weights reflect the shares an outside investor could actually buy. MSCI applies a Free Float Inclusion Factor rounded to the nearest 5% band above 15%; S&P Dow Jones uses an Investable Weight Factor with the same principle. Free-float rules also drive minimum-float requirements for listing and continued index membership.
Worked example
A company has 100,000,000 shares outstanding. The founding family holds 20,000,000 shares and a strategic partner holds 10,000,000 — 30,000,000 restricted in total. Free float = 100M − 30M = 70,000,000 shares (70%). At a share price of $50, free-float market cap = 70M × $50 = $3.5 billion; total market cap = 100M × $50 = $5.0 billion. Index weight uses the $3.5B figure.
Frequently asked questions
What counts as a restricted or non-float share?
Broadly, any shares that are not freely tradable by the public. That typically includes founder and insider holdings (executives, directors, and their families), strategic stakes held by other companies or holding vehicles, government or sovereign-fund holdings, employee shares still inside a lock-up period after an IPO, and treasury shares held by the company itself. Different index providers apply slightly different rules — MSCI treats a 5%+ block held by a strategic investor as restricted; S&P uses similar thresholds. Check the company's "major shareholders" disclosure for the current breakdown.
Why does free float matter for index inclusion?
Because an index constituent's weight must reflect what investors can actually buy. If a company has $50B in market cap but $40B is locked up with a founding family, only $10B is truly available. Weighting by total market cap would force index-tracking funds to try to buy shares that do not trade, driving up prices and creating an illiquid position. Free-float weighting solves this: MSCI, S&P, FTSE Russell, and Stoxx all use free-float-adjusted market cap. Companies with very low free float (<15%) can be excluded from major indices entirely.
What is a "good" free-float percentage?
For index investability, most providers prefer 25%+ free float; below 15% often triggers exclusion. For a shareholder, higher float generally means better liquidity, tighter bid-ask spreads, and less price volatility from single-order flow. Mature blue chips typically have 70–95% free float. Family- or founder-controlled companies (Meta, Ford, LVMH) often sit around 20–50%. Recent IPOs frequently start below 20% and rise as post-IPO lock-ups expire — usually 90–180 days after listing.
What is the difference between free float and public float?
They are essentially the same concept with different regulatory framing. "Public float" is the SEC's term (defined in Rule 405 of Regulation C) — non-affiliated shares × price, used to determine large-accelerated filer status. "Free float" is the index-provider and international-markets term with the same core idea. In everyday usage they are interchangeable; the small differences are around how "affiliate" or "strategic holder" is defined. If a question is about SEC filing thresholds, use "public float"; if it is about index weighting or trading liquidity, use "free float".
How does the free float change over time?
Free float is dynamic. It increases when insiders or strategic holders sell (or when lock-up periods expire after an IPO or a secondary offering). It decreases when the company buys back shares (reducing total shares outstanding while insiders keep their positions), when a new strategic investor takes a large block, or when a founder increases their stake. Index providers rebalance quarterly or semi-annually to reflect the current free float, which is why a company's index weight can change even without a share-price move.
Why does very low free float increase volatility?
Thin float means fewer shares available to absorb buy or sell orders. A single large order can move the price disproportionately because the liquidity pool is small. Low-float stocks also tend to have wider bid-ask spreads and are more susceptible to short squeezes, corners, and momentum-driven runs. Traders sometimes deliberately target low-float names for volatility; institutional investors usually avoid them for the same reason. Below roughly 15% free float, a stock behaves more like a private company with a public price tag than a true public equity.