Piotroski F-Score explained: nine tests of financial strength

The Piotroski F-Score is a checklist that rates a company's financial strength from 0 to 9 by awarding one point for each of nine pass-or-fail tests drawn from the financial statements. It was developed by accounting professor Joseph Piotroski, who published it in the Journal of Accounting Research in 2000. It was designed as a simple way to separate companies with improving fundamentals from those with deteriorating ones, particularly among cheap, out-of-favor stocks.

The nine tests

The tests fall into three groups. A company scores one point for each test it passes and zero for each it fails.

Profitability (four tests)

1. Positive return on assets. Net income is positive for the latest year (ROA above zero).
2. Positive operating cash flow. Cash generated by operations is above zero.
3. Improving return on assets. ROA is higher than in the prior year.
4. Cash earnings exceed accounting earnings. Operating cash flow is greater than net income, a check on accruals. When profits are backed by cash, they are generally regarded as higher quality.

Leverage, liquidity and funding (three tests)

5. Lower leverage. Long-term debt relative to assets decreased compared with the prior year.
6. Better liquidity. The current ratio is higher than in the prior year.
7. No new shares issued. The company did not issue new common stock in the past year, which indicates it did not need outside equity to fund itself.

Operating efficiency (two tests)

8. Higher gross margin than in the prior year.
9. Higher asset turnover than in the prior year.

Details of the definitions can differ between sources. In the original study, ROA was based on income before extraordinary items and scaled by assets at the start of the year, and some data providers adjust the exact inputs. For the underlying measures, see return on assets, the current ratio and asset turnover.

Example (illustrative numbers)

Consider a fictional manufacturer, scored on its latest year against the prior year.

A score of 7 is well above the middle of the range. The two failures are the sort of small slips that a sensible reader would weigh: liquidity and turnover slipped slightly while profitability, cash flow, debt and margins all improved.

How to read it

Cutoffs vary by source and are conventions, not laws. A common rule of thumb:

• 8 or 9: strong financial position and improving trend.
• 3 to 7: mixed or average. Some practitioners treat 7 as good.
• 0 to 2: weak or deteriorating.

In Piotroski's original research the scores were used to sort a universe of stocks with high book-to-market ratios, meaning companies that looked cheap relative to their accounting equity. Among those, higher-scoring firms tended to have better subsequent results than lower-scoring ones in the sample the study covered. That is a statement about historical averages in a specific group of stocks, not a promise about any one company or future period.

The score is best used as a screening aid: a quick way to flag companies whose fundamentals are strengthening or weakening, followed by deeper research into the reasons.

Common mistakes and limits

It measures change, not level. Most tests compare this year with last year. A company can earn a high score while still being weak in absolute terms, for example by improving from a very low base. Conversely, an excellent business that is already at peak margins can fail the "improvement" tests simply because there is little room to improve.

Binary tests ignore size. A margin that rose by 0.01 percentage points earns the same point as one that rose by 5 points. A current ratio that improved from 0.5 to 0.51 counts the same as one that improved from 1.0 to 2.0.

Sensitive to one-off events. A single large write-down, acquisition or equity issue can change several tests at once.

Not designed for every industry. The test uses ratios, such as current ratio and gross margin, that do not apply neatly to banks, insurers and some asset-light firms.

Evidence is limited to the original context. The research focused on low price-to-book stocks over a particular period. Results elsewhere are not guaranteed, and a well-known score can lose its edge as more investors use it.

It is not a valuation. A company with a perfect 9 can still be expensive. The score says nothing about price, so pair it with valuation work such as fair value analysis.

Complementary tools. For a different angle on safety, compare with the Altman Z-Score, which estimates distress risk, and the Beneish M-score, which looks for signs of earnings manipulation.

Where to see it on StocksXray

The F-Score is a concept covered here for education. The site takes a related but different approach: the X-Ray Score ranks each company on profitability, financial health and other lenses using percentile ranks within the sector, rather than nine pass-or-fail tests. The fundamentals checklist on each stock page labels metrics Good, Average or Bad against sector peers. See the methodology page.

Key takeaways

• The F-Score gives one point for each of nine tests covering profitability, leverage and liquidity, and operating efficiency.
• A score of 8 or 9 is generally considered strong and a score of 0 to 2 weak, as rules of thumb; cutoffs vary by source.
• It mostly measures year-over-year improvement, so the level of quality still needs checking.
• Pass-or-fail scoring ignores the size of changes and does not account for price.
• Use it to flag companies for research, not as a standalone decision.