What Is Janka Hardness? A Simple Guide to Wood Hardness

If you have ever compared different types of lumber, you may have come across numbers such as 350, 950, 1,290, or 3,680 next to different wood species. These numbers are usually related to the Janka hardness test, a common way of comparing how hard a piece of wood is.

So, what do those numbers actually mean?

In simple terms, the Janka hardness rating tells you how much force is needed to push a standard steel ball partway into a piece of wood. The higher the number, the harder the wood is.

That information can be useful when choosing lumber for flooring, furniture, decking, stairs, cabinets, and other projects where the wood may be exposed to dents, impacts, or everyday wear.

But hardness is only one part of choosing the right wood. A high hardness number does not automatically mean that a species is the best choice for every project.

Key Takeaways

• Janka hardness measures how resistant wood is to indentation, making it useful for comparing different wood species.
• Higher Janka values mean harder wood, while lower values indicate softer wood that may dent more easily.
• Hardness is not the same as durability. A wood can be hard but still need protection from moisture, insects, or decay.
• Harder woods are often useful for flooring and decking, while softer species can be excellent for siding, cladding, and other applications.
• Popular woods vary widely in hardness, from very soft balsa and cedar to extremely hard species such as ipe, lignum vitae, and quebracho.

Janka Hardness at a Glance

Here is a quick comparison of commonly used wood species. Values can vary somewhat depending on the specific species, grade, source, and testing direction.

Popular Wood Species	Janka Hardness (lbf)
Balsa	100
Aspen	350
Western Red Cedar	350
Eastern White Pine	380
White Pine	380
Basswood	410
Redwood	450
Ponderosa Pine	460
Cypress	510
Sitka Spruce	510
Poplar	540
Red Alder	590
Hemlock	540
Douglas Fir	660
Spruce	380–490
Fir	660
Sycamore	770
African Mahogany	830
Southern Yellow Pine	870
Mahogany	900
Honduran Mahogany	900
American Cherry	950
Soft Maple	950
Red Maple	950
Black Walnut	1,010
Teak	1,070
Andiroba	1,130
Iroko	1,260
Yellow Birch	1,260
Birch	1,260
Red Oak	1,290
Beech	1,300
White Ash	1,320
White Oak	1,360
Hard Maple	1,450
Sapele	1,410
Afrormosia	1,560
Garapa	1,650
Lacewood	1,700
Black Locust	1,700
Padauk	1,725
Zebrawood	1,830
Pecan	1,820
Hickory	1,880
Jarrah	1,910
Wenge	1,930
Canarywood	1,900
Merbau	1,840
Tigerwood	2,160
Leopardwood	2,150
Goncalo Alves	2,170
Santos Mahogany	2,200
Jatoba / Brazilian Cherry	2,350
Bubinga	2,410
Spotted Gum	2,470
Purpleheart	2,520
Greenheart	2,690
Brazilian Rosewood	2,790
Cocobolo	2,960
Angelim Pedra	3,040
Bloodwood	2,900+
Bulletwood	3,130
Massaranduba	3,190
Ebony	3,220+
Cumaru / Brazilian Teak	3,330–3,540
Grey Ironbark	3,600
Ipe / Brazilian Walnut	3,680
Katalox	3,660
Verawood	3,710
Snakewood	3,800
Lignum Vitae	4,390
Quebracho	4,570

Quick rule: lower number = softer wood, higher number = harder wood.

What Is Janka Hardness?

The Janka hardness test was developed to measure the resistance of wood to indentation.

The test uses a steel ball with a diameter of about 0.444 inches. The ball is pressed into the wood until it reaches a specified depth. The amount of force required to reach that point is recorded as the wood’s hardness value.

The result is normally given in pounds-force (lbf) in the United States.

For example, if a wood has a Janka rating of 1,000 lbf, it takes considerably more force to make the standard indentation than it would in a wood rated at 400 lbf.

That gives buyers, builders, woodworkers, and flooring professionals a simple number for comparing different species.

Best Wood Species by Application

100 = best choice for that application.

Wood Species	Decking	Flooring	Siding	Cladding	Pergolas	Patio
Cedar	90	70	100	100	100	90
Redwood	88	72	98	98	96	88
Ipe	100	100	70	70	85	100
Cumaru	98	96	68	68	83	98
Teak	96	88	72	72	95	96
Mahogany	90	85	90	90	88	90
Sapele	88	83	88	88	85	88
White Oak	78	94	82	82	80	78
Southern Yellow Pine	82	75	78	75	80	82
Douglas Fir	75	72	80	80	78	75
Black Walnut	65	92	60	60	65	65
Hard Maple	68	95	55	55	60	68
Poplar	45	65	60	60	50	45
Hemlock	55	60	65	65	62	55

How to read it: The score is a practical suitability rating out of 100, with 100 representing the strongest overall choice for that particular application.

Why Does Wood Hardness Matter?

The main reason people care about wood hardness is everyday wear.

A harder wood generally has greater resistance to dents and indentation. This can be useful for surfaces that regularly experience pressure or impact.

Think about a hardwood floor in a busy home. Shoes, furniture, pets, dropped objects, and daily foot traffic can all leave marks. A harder species may hold up better against this type of use.

The same idea applies to stair treads, tables, work surfaces, and some types of decking.

However, there is a trade-off.

Very hard wood can also be more difficult to cut, drill, sand, and install.

What Does a High Janka Rating Mean?

A high rating generally means that the wood is harder and more resistant to indentation.

For example, ipe has a much higher rating than cedar. If both are exposed to a similar impact, the ipe surface is generally less likely to dent.

Harder wood can be useful when:

• The surface receives heavy foot traffic
• Furniture is frequently moved
• The material needs to resist dents
• The project requires a hard wearing surface
• You want a flooring species that handles everyday abuse well

But a high rating does not tell you everything about the wood.

A species with excellent hardness may still be unsuitable for a particular outdoor environment if it has poor moisture resistance or requires maintenance that does not fit the project.

What Does a Low Janka Rating Mean?

A lower number indicates softer wood.

Softer species are generally easier to work with, but they can be more susceptible to dents and scratches.

Western red cedar is a good example. It has a relatively low hardness rating, but that does not make it a bad building material.

Cedar is valued for other characteristics, including its light weight, workability, appearance, and natural resistance to decay.

This is an important point when comparing lumber: soft does not mean bad, and hard does not mean automatically better.

How Is the Janka Test Performed?

The basic test sounds complicated, but the idea is straightforward.

A small steel ball is pressed into a sample of wood. The test measures the force required to push the ball to a standard depth.

The resulting force becomes the hardness rating.

There are also different ways the test can be performed depending on the surface and direction being tested.

Wood is not perfectly uniform. Its hardness can differ depending on whether the test is performed on the surface perpendicular to the grain or on a surface that runs parallel to the grain.

This is why Janka figures should be treated as useful comparison points rather than absolute numbers that describe every piece of lumber perfectly.

Why Does the Direction of the Grain Matter?

Wood grain has a major effect on how wood responds to pressure.

The standard hardness figure commonly reported for lumber is generally based on testing the surface perpendicular to the grain, often referred to as the side hardness.

There is also an end-grain test, where the steel ball is pressed into the end of the wood.

The two measurements can be different.

For everyday lumber comparisons, the standard side-hardness figure is usually the number people are looking for.

Janka Hardness vs. Wood Durability

These terms are sometimes treated as if they mean the same thing, but they do not.

Hardness describes resistance to indentation.

Durability is a much broader concept.

Durability can include resistance to:

• Rot
• Fungi
• Insects
• Moisture
• Weather
• Wear
• Decay

For example, cedar is softer than many hardwoods, but certain cedar species have good natural resistance to decay.

Ipe has both high hardness and strong natural resistance to many outdoor conditions, which is one reason it is popular for premium decking.

So if you are choosing wood for an outdoor project, do not look at the hardness number alone.

Is Harder Wood Always Better?

No.

It is tempting to assume that the highest number on a wood hardness chart must be the best option. In practice, the right choice depends on the job.

A very hard tropical hardwood can be excellent for decking but may be unnecessary for a decorative indoor project.

Likewise, a softer wood can be perfectly suitable for siding, wall paneling, or a project where ease of installation matters more than resistance to dents.

Price, availability, appearance, stability, workability, and moisture resistance all deserve consideration.

How Janka Rating Helps With Flooring

Wood flooring is one of the areas where hardness ratings are particularly useful.

A floor can receive years of foot traffic, and softer wood may show dents and scratches more quickly.

Harder species such as hickory, hard maple, and oak are popular in flooring because they can handle regular use.

Softer woods can still be used successfully. In fact, some homeowners deliberately choose softer species because they like the character and appearance that develop as the floor ages.

Small dents and marks are not always viewed as damage. They can become part of the character of a natural wood floor.

How Janka Rating Helps With Decking

For decking, hardness can be useful because the boards are exposed to foot traffic, outdoor furniture, and general wear.

Dense hardwoods such as ipe can score very high on a wood hardness chart and are known for their ability to withstand heavy use.

But outdoor decking needs more than hardness.

The wood also has to deal with rain, humidity, sunlight, temperature changes, and insects. A species with high hardness but poor outdoor durability may not be a practical choice.

That is why decking decisions should consider both hardness and natural durability.

Does Hard Wood Last Longer?

Not necessarily.

Hardness can help a surface resist dents, but it does not determine the entire lifespan of the wood.

A very hard piece of wood can still deteriorate if it remains constantly wet or is installed in a way that traps moisture.

Likewise, a softer species can last for many years when it is naturally resistant to decay and properly installed.

The environment matters enormously.

For outdoor projects, drainage, ventilation, installation, exposure, and maintenance can have a major effect on service life.

Hardness and Workability

One of the biggest practical differences between soft and hard wood is how easy they are to work with.

Softer wood is usually easier to:

• Cut
• Drill
• Sand
• Nail
• Screw
• Shape

Very dense hardwoods can require sharper tools and more care during installation.

Some dense tropical woods can also be harder on cutting tools. Pre-drilling may be recommended for certain applications.

So while a high hardness rating can be desirable for the finished product, it may mean more effort during construction.

Does Hardness Affect Scratches?

Yes, but not completely.

Harder wood generally resists indentation better, but scratches depend on more than the species’ hardness.

The finish, surface texture, object causing the scratch, and amount of force involved all matter.

A sharp object can scratch even a very hard wood.

This is another reason the hardness number should be viewed as one piece of information rather than a complete prediction of how a finished surface will behave.

Does Hardness Affect Wood Prices?

Sometimes, but there is no direct pricing formula based on hardness.

A wood species can be expensive because of rarity, availability, transportation, demand, appearance, sourcing, or other factors.

Ipe, for example, has a very high hardness rating and is often sold as a premium decking material. But its price is influenced by many things beyond that number.

Domestic species such as oak or maple can offer a different balance of hardness and cost.

When comparing lumber, look at the total value rather than assuming a higher rating always means a better deal.

How to Choose the Right Hardness for Your Project

Start with the actual conditions the wood will face.

For a high-traffic floor, a harder species may be worthwhile.

For outdoor decking, consider hardness together with decay and moisture resistance.

For siding, extreme hardness may not be necessary at all.

For furniture, think about how the piece will be used. A dining table may benefit from a harder surface, while a decorative cabinet may not need the same level of resistance.

For woodworking, workability can be just as important as hardness.

A wood that is difficult to machine may slow down the project even if it has excellent physical properties.

A Simple Way to Read a Wood Hardness Chart

You do not need to memorize dozens of numbers.

Instead, use the ratings as a rough comparison.

• Below 500 lbf: generally softer woods
• 500–1,000 lbf: soft to moderately hard
• 1,000–1,500 lbf: moderately hard to hard
• 1,500–2,000 lbf: hard
• Above 2,000 lbf: very hard

These are broad categories rather than official classifications. They are simply a convenient way to understand where different woods sit on the scale.

For example, cedar at around 350 lbf is much softer than red oak at around 1,290 lbf. Ipe, at around 3,680 lbf, is in another category altogether.

Other Factors to Check Alongside Janka Hardness

Before buying lumber, look at the complete set of characteristics.

Moisture resistance: Important for outdoor projects.

Decay resistance: Particularly important when wood will be exposed to damp conditions.

Dimensional stability: Tells you more about how the wood responds to moisture changes.

Workability: Determines how easy it is to cut and install.

Grain and appearance: Important for furniture, flooring, siding, and visible surfaces.

Cost: A wood may perform exceptionally well but exceed your project budget.

Availability: A species that is difficult to source may not be practical for a large project.

Common Misunderstandings About Wood Hardness

One common misconception is that every hardwood has a higher rating than every softwood.

That is not true.

The terms hardwood and softwood describe broad botanical groups, not a simple ranking from soft to hard.

Some softwoods are harder than certain hardwoods.

Another misconception is that hardness equals strength.

They are different properties. A wood can be hard without being the strongest choice for a particular structural application. Hardness also does not tell you how resistant a species is to termites, rot, or moisture.

For a serious construction project, the complete specifications of the lumber should be considered.

FAQs About Janka Hardness

What is the Janka hardness test used for?

It is used to compare how much force different wood species can withstand before being indented.

What is considered a good Janka hardness rating?

It depends on the application. A rating that works well for siding may not be enough for a heavily used floor or deck.

Is Janka hardness measured in pounds?

In the United States, wood hardness is commonly reported in pounds-force (lbf). Some references also provide values in newtons.

What is the softest wood on the Janka scale?

Balsa is among the softest commonly known woods, with a Janka hardness of roughly 100 lbf.

What is one of the hardest commercially available woods?

Species such as lignum vitae, quebracho, and certain ebony species have exceptionally high hardness ratings.

Is cedar considered a hard wood?

No. Cedar is generally considered a softwood and has a relatively low Janka hardness rating, but it is valued for other properties such as natural decay resistance and workability.

Is ipe harder than oak?

Yes. Ipe has a substantially higher Janka hardness rating than common oak species, making it much more resistant to indentation.

Does a higher hardness rating mean wood is stronger?

Not necessarily. Hardness measures resistance to indentation, while strength describes how wood handles forces such as bending, compression, or breaking.

Does moisture affect Janka hardness?

Yes. Wood hardness can change with moisture content, which is why Janka results are normally reported under standardized testing conditions.

Can Janka hardness help me choose wood for a project?

Yes. It is particularly useful when comparing lumber for flooring, decking, stairs, furniture, and other surfaces where resistance to dents and wear matters.

Conclusion

The Janka hardness rating is a useful way to understand how well a wood surface may resist indentation. It gives you a simple number that makes it easier to compare species that can otherwise be difficult to judge side by side.

A higher rating generally means harder wood and better resistance to dents. A lower rating usually indicates softer wood that may be easier to work with but more prone to indentation.

The important thing is not to treat the number as the final answer.

If you are choosing lumber for flooring, decking, furniture, siding, or another project, look at hardness alongside decay resistance, moisture resistance, stability, workability, appearance, availability, and cost.

That broader view will tell you much more about whether a particular species is right for the job. A hardness chart can narrow down your options, but the best wood is ultimately the one whose characteristics match the environment and the way you plan to use it.