Enter the early finish date of the activity and the early start date of the successor activity into the calculator to determine the free float (in days).
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Free Float Formula
The calculator runs in two modes. Each mode uses its own formula.
Stock free float (shares):
Free Float = Outstanding Shares - Restricted Shares - Closely Held Shares
Free Float % = (Free Float / Outstanding Shares) * 100
Project schedule free float (days):
FF = ES(successor) - EF(activity)
If you do not know the activity early finish, the calculator computes it first:
EF = ES(activity) + Duration
Variables:
- Outstanding Shares: total shares the company has issued.
- Restricted Shares: shares locked by law or contract (insider lockups, employee restricted stock, etc.).
- Closely Held Shares: shares held by insiders, governments, or strategic owners who do not trade them on the open market.
- ES(successor): early start of the immediate successor activity.
- EF(activity): early finish of the activity you are analyzing.
- ES(activity): early start of the activity.
- Duration: how long the activity takes, in days.
The Stock shares tab subtracts non-float shares from outstanding shares and reports the percentage. The Project schedule tab subtracts the activity early finish from the successor early start and returns days of slack. You can enter day numbers or calendar dates, and you can either type the activity early finish directly or let the calculator add duration to the early start.
Reference Tables
Use these as quick checks against your inputs and results.
Stock free float interpretation
| Free Float % | Typical Read | Liquidity Note |
|---|---|---|
| Below 10% | Very tightly held | Wide spreads, high volatility |
| 10% to 25% | Low float | Index inclusion often blocked |
| 25% to 50% | Moderate float | Acceptable for many indexes |
| 50% to 75% | Healthy float | Active trading expected |
| Above 75% | High public float | Tightest spreads, deepest book |
Schedule free float interpretation
| Free Float Value | Meaning | Action |
|---|---|---|
| Negative | Activity finishes after successor starts | Fix logic or compress duration |
| Zero | No slack before next activity | Any delay hits the successor |
| 1 to 3 days | Tight buffer | Monitor closely |
| More than 3 days | Comfortable buffer | Standard tracking |
Examples and FAQ
Example 1: Stock free float. A company has 10,000,000 outstanding shares. Insiders hold 2,500,000 closely held shares and there are 1,000,000 restricted shares from a recent IPO lockup. Free float = 10,000,000 − 1,000,000 − 2,500,000 = 6,500,000 shares. Free float percentage = 6,500,000 / 10,000,000 × 100 = 65%.
Example 2: Schedule free float. Activity B has an early start of day 5 and a duration of 4 days, so its early finish is day 9. Its immediate successor, Activity C, has an early start of day 12. Free float = 12 − 9 = 3 days. Activity B can slip up to 3 days without delaying Activity C.
How is free float different from total float? Free float is the delay an activity can absorb without pushing its immediate successor. Total float is the delay it can absorb without pushing the project finish. Free float is always less than or equal to total float.
Does free float include treasury shares? No. Treasury shares are not part of outstanding shares, so they never enter the free float calculation. If a data source reports “issued” shares instead of “outstanding,” subtract treasury stock first.
Can free float be negative on a schedule? Mathematically yes, and the calculator will show it. A negative result means the predecessor finishes after the successor is supposed to start, which is a logic error in the schedule that needs fixing.
What counts as closely held? Generally shares owned by company officers, directors, controlling shareholders, governments, parent companies, and strategic partners. Index providers like S&P and FTSE publish their own thresholds, but most exclude holdings above 5% from the float.
