The Janka hardness scale measures how well a wood resists denting. The test records the force needed to press a 0.444-inch steel ball halfway into a wood sample, reported in pounds-force (lbf) the higher the number, the harder the wood. For flooring, roughly 1,000 lbf is the practical minimum, red oak at 1,290 is the industry benchmark, and 1,360 and up (white oak and harder) suits busy households. Here is how the scale works, a full flooring chart, and what the number does and does not tell you.
At National Hardwood Flooring & Moulding, we have helped Southern California buyers use the Janka scale to choose the right species since 1984. Browse our full hardwood flooring range, or read on for the complete guide.
What Is the Janka Hardness Scale?
The Janka scale is the industry-standard measure of wood hardness. It is named after Gabriel Janka, the Austrian-born researcher who developed the test in the early 1900s. The scale answers one specific question: how much force does it take to dent this wood? A higher Janka number means a harder, more dent-resistant surface, which is why it is the first spec people compare when choosing hardwood flooring.
How the Janka Test Works
The method is precise. A steel ball 11.28 millimeters (0.444 inch) in diameter is pressed into a wood sample until it is embedded to exactly half its diameter an indentation of one square centimeter and the force required is recorded. Under ASTM standards the test uses clear, knot-free samples conditioned to 12 percent moisture content, measured on the face of the board (“side hardness”), which is the surface you actually walk on. The result is a single number: the force it took to make that dent.
Janka Hardness Chart for Flooring Species
Here is how common flooring species rank, from softest to hardest. Use it as a general guide real-world ratings vary with species, growing conditions, and testing.
| Wood species | Janka (lbf) | Note |
| Douglas fir | ~660 | Softwood — below flooring minimum |
| American black walnut | ~1,010 | Soft for a hardwood; low-traffic rooms |
| Red oak | 1,290 | Industry benchmark |
| White oak | 1,360 | Busy-household ready, very stable |
| Hard maple | ~1,450 | Harder than oak; bright, modern |
| Hickory | 1,820 | Hardest common domestic species |
| Acacia | ~1,700–2,300 | Hard exotic, value-priced |
| Brazilian cherry (Jatoba) | ~2,350–3,500 | Very hard; darkens in sun |
| Brazilian walnut (Ipe) | ~3,684 | Among the hardest; mostly decking |
For the full story on any of these, see our species guides: hickory vs. oak, walnut, maple, Brazilian cherry, and acacia.
What Is a Good Janka Rating for Flooring?
A few practical benchmarks:
- ~1,000 lbf is the general minimum most experts recommend for a floor.
- Red oak at 1,290 is the industry benchmark — the reference point every other species is compared against.
- 1,360 and up (white oak and harder) comfortably handles kids, pets, and heavy foot traffic.
Below about 1,000, a wood is better suited to low-traffic rooms or non-flooring uses. But a lower number does not mean poor quality — walnut, at roughly 1,010, is a beautiful, sought-after floor in the right room.
The Units Trap: lbf vs. Newtons vs. kgf
This trips up more buyers than anything else on the scale. The same test is reported in different units around the world — pounds-force (U.S.), newtons, or kilograms-force — often with no unit attached. So a floor advertised at “6,000” is not five times harder than one at 1,360. It is most likely the very same white oak, just reported in newtons.
When you compare Janka numbers, make sure they are all in the same unit — in the U.S., that is lbf. If a number looks impossibly high, it is almost certainly newtons. Ask the supplier which unit they are quoting.
What Janka Does NOT Tell You
The Janka number is useful but narrow. Three things it does not measure:
- Scratch resistance. Janka predicts DENT resistance, not scratches. Scratch resistance comes mostly from the finish, which is why manufacturers do not warranty wood against scratching. A very hard floor with a weak finish can still scratch.
- Hardness says nothing about how much a wood expands and contracts with humidity. Hickory is very hard but moves a lot; white oak is softer but more stable.
- Overall quality. Harder is not automatically better. The right floor balances hardness with the look, stain behavior, and stability you need.
Hardness Isn’t Everything: Stability, Staining, and Refinishing
Choosing a floor on Janka alone is a mistake. A harder wood resists dents but may be harder to stain evenly (like maple), less stable in humidity (like hickory), or prone to color change (like Brazilian cherry). In Southern California’s variable climate, stability often matters as much as hardness, which is why we frequently recommend engineered construction. The best choice weighs all of these together.
Janka Hardness FAQ
What are the top hardest woods?
Among woods used in or near flooring, Brazilian walnut (Ipe) at about 3,684 lbf is among the hardest, followed by Brazilian cherry (Jatoba) and other dense exotics. Balsa, at around 100, sits at the opposite extreme.
What is the hardest wood in America?
Among common domestic flooring species, hickory is the hardest at about 1,820 lbf, ahead of maple, white oak, and red oak.
What is a good Janka rating for hardwood floors?
About 1,000 lbf is the practical minimum, red oak’s 1,290 is the industry benchmark, and 1,360 or higher suits busy households.
Does a higher Janka rating mean a better floor?
Not necessarily. Janka only measures dent resistance. Stability, staining, finish, and looks matter just as much, so the best floor balances all of them.
Use the Scale — Then See the Wood in Person
The Janka scale is a great starting point, but numbers only go so far. Visit our Van Nuys showroom to compare species side by side across grades, finishes, and constructions, or browse our hardwood flooring range online. Contractors and designers can ask about trade pricing and bulk sourcing.
