SBC stands for stock-based compensation: paying employees partly in shares instead of cash. This ratio compares that share-pay bill to the company's free cash flow, and it reads directly: 10% means the shares handed out in a year are worth a tenth of the free cash flow, 25% means a quarter, and so on.
Why it needs watching: free cash flow only counts actual cash, and when employees are paid in shares, no cash leaves. Picture a coffee shop that generates $50,000 of spare cash a year. Instead of paying the manager a $5,000 cash bonus, the owners give her a stake in the shop worth $5,000. The till still shows the full $50,000, so on paper nothing was spent, but the owners now hold slightly thinner slices of the shop. That is SBC/FCF of 10%: a real cost, paid in ownership instead of cash.
This number is not the dilution percentage. If that shop is worth $500,000, the $5,000 stake handed to the manager is only 1% of the shop, so the owners were diluted by 1%, even though SBC/FCF reads 10%.
How to read it: • Below 10%: healthy, typical of mature businesses • 10% to 25%: meaningful, common in tech, and worth tracking • Above 25%: share pay is taking a large bite out of owner returns
Never read it alone. Pair it with net share change: SBC is the dilution tap, net share change is the final water level. A tech company with SBC/FCF of 19.5% and a net share change of −5.1% issues new shares to staff constantly, yet buybacks removed them all and more, so owners came out ahead. The bad picture is the reverse: high SBC and a rising share count.