The 4 Best Whetstones for Sharpening Dull Blades, According to Our Tests

Our Favorite Whetstone

The King Whetstone Starter Set is a good choice for beginners and experienced users alike, providing a good selection of grits on a sturdy, dual-sided stone (and at a reasonable price). It may be a little short for longer knives, but this didn’t show itself to be too problematic.

How We Tested Whetstones

To test 20 whetstones, we needed a lot of dull knives — many more than we had on hand in our kitchens. So, to start, we dulled several new Henckles 8-inch chef’s knives using a coarse-grit sharpener set at a 35° angle. After establishing that each knife was sufficiently dull, using a professional knife edge tester that measures the grams of pressure necessary to cut through a thread, we put them through a series of tests to assess the blade’s performance before and after its whetstone sharpening.

First, we sliced — or attempted to slice — through a sheet of paper, running the knife from heel to tip and slicing lengthwise through the sheet suspended in our hand. Next, we cut carrots three ways: into thin rounds, lengthwise into halves and quarters, and then we attempted a fine julienne before cross-cutting to brunoise. In our final test to confirm their dullness, we used the knives to thinly slice a tomato, if possible. After testing each whetstone by sharpening these dull blades, we used the edge tester to measure the blade’s new sharpness at its tip, middle, and heel before repeating the cutting tests of paper, carrots, and tomatoes. 

With that information in hand, we then rated the whetstones on a scale of one to five in the following areas:

• Design: This included the material of each stone’s composition, its perceived durability, ranges of grits from coarse to fine, manufacturer’s guidance on what you can or shouldn’t sharpen on the stone, any included accessories that made sharpening easier (such as edge guides, dressing stones, or stands), and the whetstones’ size(s).
• Ease of Use: We used this grouping to rate the quality of any included instructions, how easy each stone might be for a beginner to use, if the stone and base (if included) were stable or wobbly, and if any grit was better or worse than others when using them.
• Performance: For this area, we considered how quickly each whetstone developed a slurry, how many strokes were required to raise and smooth the burr on each blade, the knives’ beginning and end sharpness ratings, and the results of each cutting test before and after the blades were sharpened. 

We used these ratings and some additional subjective observations to arrive at our winners in each category — along with the ones that we thought were good but didn’t quite make the grade and those that we felt needed some improvement.

Factors to Consider

How to Use a Whetstone

You have to develop a feel for using a sharpening stone. That said, we have a general set of instructions here. For a quick summary, you’ll first soak, wet, or oil your stone to provide proper lubrication for the metal-on-stone friction that’s about to occur. Then, you’ll start with the lowest-numbered grit, which is the coarsest stone in your set. This stone will raise a burr on the blade, which forms when you sharpen one side of the blade to the point that the edge starts to curl over to the opposite side. The coarse stone sets the tone for all subsequent work, so don’t skip it.

Next, set your knife at the proper angle, typically 15° for Japanese knives or 20° for Western-style blades. Apply two to four pounds of pressure to the blade by pressing down and, starting at the tip or the heel, run the knife the length of the stone. In the same motion, you’ll move along the blade towards the opposite end from that you started with to ensure you’re sharpening the blade’s entirety. Repeat this motion until you can feel the burr raising on the opposite edge of the blade. Fifty to 80 strokes should be sufficient. Then, turn the knife over and repeat this process to smooth the burr and establish the edge.

Repeat these steps on each successive stone until you’ve reached the highest numbered grit. As you’re going up in grit, you’re no longer trying to raise the burr but refine the edge that you set with the first coarse stone, so you can apply lighter pressure when using higher-numbered grits. To finish, you can run the knife across a leather strop or honing steel to remove any remaining inconsistencies in the blade.

Ease of Use

Learning to use a whetstone can be daunting, so finding a set or stone that’s easy for you to use helps greatly. If you’re new to the whole experience, an angle guide can help you get used to holding the knife at the proper angle. A stand to elevate the stone from the counter or tabletop gives you more room to position your hands to maintain that angle. But the stand should preferably have a slip-resistant bottom to keep it from sliding around and a form-fitting insert or clamp to hold the stone in place on top of the stand. Some sets are dual-sided, and others have two or more stones in the collection. If you’re prone to accidentally separating or misplacing things in a kitchen drawer, a dual-sided stone may help you out.

Grit and Blade Sharpness

The duller your blade, the coarser (lower numbered) the grit you’ll need to sharpen it. If you stay on top of your knives and notice they don’t quite slice a tomato as easily as last week, a quick touch-up on a finer grit stone will get you right back to where you were. But if your knives are significantly dull, you’ll need a coarser grit to bring them back into shape. 

The coarse grit sets the tone for what’s to come. If your knife is simply dull and doesn’t require repair, like fixing a chipped tip or nicked blade, a good starting point is between 800 and 1,000 grit. You’ll raise the burr and establish the edge with the coarse grit, then polish and refine the edge to greater degrees of sharpness with medium and fine grits: 3,000 is good for a medium grit, while 6,000-8,000 will put the finest edges on your blade.

You can buy higher grit stones, but unless you have a need for surgically sharp knives or use them for carving or woodworking, 8,000 should be more than adequate to sharpen your knives for home or professional use. If you’re a beginner, keep these numbers in mind as a starting point, and you can customize your selections when you feel more comfortable and can better identify your needs.

Stone Length

Efficiently sharpening your knives, meaning sharpening the whole blade at once, requires you to have the range to move the knife from tip to heel as you stroke it down the length of the stone. Whetstones that are shorter or the same length as your knife can frustrate your efficiency efforts, making you spend extra time focusing on particular regions of the blade that didn’t receive the same stone contact or pressure. Consider buying a stone two inches or more longer than your knife blade. An 8-inch stone is great for a 6-inch petty knife but can be frustrating with an 8-inch chef’s knife, for example.

Care

Whetstones are rocks. What could be complicated about caring for them? True, they are easy to care for; simply rinse them off and then clean the surface to remove any remaining slurry. But inevitably, no matter how hard you try to maintain even pressure and not work the same spot on the stone, you’ll start to wear it down unevenly. In that case, a dressing stone or fine-grit sandpaper is needed to even the stone out and remove any residual slurry that’s hardened onto the stone. If you don’t mind a separate purchase of sandpaper, that’s fine. But if you do, look for a set with a dressing stone included.

Other Whetstones We Tested

Strong Contenders

Mizuyama Sharpening Stone ($79 at Korin)
This dual-side stone set is quite minimalist, with just the stone and a rubber mat, but it produced some really great results. However, we found that the mat didn’t provide much non-slip protection, and the instability could be dangerous for beginners or the inattentive.

Keenbest Sharpening Stone Kit ($19 at Amazon)
We love that this two-stone, dual-sided set has all the grits you need to get started, but the stones needed more length to work with it efficiently. Plus, it couldn’t quite compete with the performance of our Best Value pick.

Norton IM200 Knife Sharpener Kit ($97 at Amazon)
This set includes three stones (120, 200, and 400 grit) mounted on a spindle that rotates through an oil reservoir. In addition to the lack of fine-grit stones, we found that the rotating stones needed more stability, and the oil splashed and made a mess.

 Work Sharp Whetstone ($50 at WorkSharp)
The Work Sharp is another whetstone that suffers from lack of length. The stones worked well, and this would be a fine stone for shorter knives, but an 8-inch chef’s knife took a lot of focus on each blade area to attain a uniform sharpness.

Amazon Basics Whetstone Knife Sharpening Set ($48 at Amazon)
The Amazon Basics set includes two dual-sided stones with all the grits a beginner needs, but it, too, suffers from a short length that makes evenly sharpening an 8-inch knife difficult.

What Didn't Make the List

In this round of testing, there were several whetstones that didn’t quite make the cut. Some may have started with a good idea, like including different materials for each grade of coarseness (such as diamond, aluminum oxide, and ceramic), yet they fell flat based on their results and size. This was the case with sets like the AccuSharp DELUXE Tri-Stone System.

A common thread of underperformance in testing was the shortness of some stones, which made evenly sharpening an 8-inch chef’s knife challenging. The Sharp Pebble Premium Knife Sharpening Stone was among them. Even after focusing on specific areas of the blade, the sharpness results were lackluster, and the stones required frequent re-wetting to suspend the slurry. Smith’s Tri6 Arkansas Stone Sharpening System was also too short for an 8-inch knife, and the three stones mounted on a rotating spindle construction was too wobbly to achieve even results. 

We also tested the Sharpening Supplies Double-Sided 8-Inch Water Stone Kit, which is out of stock. It has a good selection of grits with its two dual-sided stones, but we found that the stones were too narrow to sharpen an 8-inch chef’s knife in one pass. We also noticed that the coarse stone wore down quickly and, lacking a stand, wobbled when placed on a wet towel. 

Our Expertise

Greg Baker is an award-winning chef, former restaurateur, and food writer with four decades of experience in the food industry. His written work appears in Food & Wine, Tasting Table, Serious Eats, and other publications.