Diamond Crystal vs Morton: The Salt Swap Everyone Gets Wrong
September 16, 2026
You followed the recipe exactly. A tablespoon of kosher salt in the braise, just as written. And it came out like seawater — inedible, unfixable, an hour of work in the bin.
You did not mis-measure. You used the wrong brand. The recipe was developed with Diamond Crystal, and you own Morton, and those two boxes both labelled “kosher salt” hold wildly different amounts of salt in the same tablespoon.
Most articles will tell you the fix is simple: use half as much Morton. That rule is wrong, and it is wrong in the direction that leaves your food bland. Here is the real number, and the reason three reputable sources cannot agree on it.
The short answer
By the numbers our salt converter runs on, one US cup of Diamond Crystal weighs 135 g and one cup of Morton weighs 225 g. That is a ratio of 1.67, not 2.
So when a recipe calls for Diamond Crystal and you have Morton:
Use about 60% of the volume — roughly ⅗ of a teaspoon of Morton for every teaspoon of Diamond Crystal. Going the other way, use 1⅔ times the volume.
“Half” is easier to remember, and that is exactly why it spread. But halving under-salts by about 17%, which across a whole pot is the difference between seasoned and flat.
The chart
Weights per US cup, and what one teaspoon of each actually weighs:
| Salt | g per US cup | g per tbsp | g per tsp |
|---|---|---|---|
| Diamond Crystal kosher | 135 g | 8.4 g | 2.8 g |
| Coarse sea salt | 220 g | 13.8 g | 4.6 g |
| Morton kosher | 225 g | 14.1 g | 4.7 g |
| Fine sea salt | 256 g | 16.0 g | 5.3 g |
| Table salt | 288 g | 18.0 g | 6.0 g |
Note where table salt sits. It is more than twice as heavy per spoon as Diamond Crystal — a teaspoon of Diamond Crystal is a scant half-teaspoon of table salt. That swap is the one that ruins dinner outright, and it is the one people make casually.
Why the same spoon holds different amounts of salt
All salt is sodium chloride. A gram of one is exactly as salty as a gram of another. The entire problem is how the crystals stack.
Diamond Crystal is made by the Alberger process: brine is heated and agitated in open pans, and salt forms on the surface as hollow, upside-down pyramids. Cargill, which owns the brand, describes that hollow-pyramid shape as the source of its low bulk density. Those fragile pyramids cannot nest. A spoonful of Diamond Crystal is substantially air.
Morton takes the opposite route — vacuum-evaporated salt pressed between high-pressure rollers into flat, hard flakes. Flat flakes lie down against each other and pack tightly. Same spoon, far more salt.
That is also why Diamond Crystal is the professional default: hollow pyramids crush between your fingers and dissolve fast, so it is harder to over-salt by accident. NYT Cooking, Serious Eats and Bon Appétit all develop recipes with it, which is why the brand mismatch bites so often.
The disagreement worth knowing about
Here is the interesting part. Three credible sources give three different answers:
| Source | Diamond Crystal | Morton | Implied ratio |
|---|---|---|---|
| King Arthur Baking | 8 g / tbsp | 16 g / tbsp | 2.00 |
| Manufacturer nutrition labels | 8.4 g / tbsp | 14.4 g / tbsp | 1.71 |
| Our converter | 8.4 g / tbsp | 14.1 g / tbsp | 1.67 |
King Arthur’s chart is where the “exactly half” rule comes from — 8 and 16 are beautifully memorable numbers. But they are rounded to whole grams per tablespoon, and at this scale that rounding is coarse: it shaves Diamond Crystal down about 5% and pushes Morton up about 11%, and those two roundings happen to lean in opposite directions. The tidy 2x is partly an artefact of rounding.
The nutrition labels are the more direct evidence, because they come from the manufacturers measuring their own product. Diamond Crystal’s box label gives a ¼ tsp serving as 0.7 g; Morton’s gives ¼ tsp as 1.2 g. That is 2.8 g and 4.8 g per teaspoon — a ratio of 1.71.
And you can check those figures against themselves. Pure sodium chloride is 39.3% sodium by mass. Diamond Crystal’s 0.7 g should carry 275 mg of sodium; the label says 280 mg. Morton’s 1.2 g should carry 472 mg; the label says 480 mg. Both line up. The gram figures are real measurements, not marketing rounding.
Our converter sits at 1.67 because it uses 135 g and 225 g per cup — within a couple of percent of the labels, and squarely inside the range you could measure yourself. Anywhere in the 1.65–1.75 band is defensible. The one number that is not defensible is 2.
Just weigh it
Every argument on this page evaporates if you own a scale. Salt is the ingredient with the widest volume-to-weight spread in your kitchen — a 2.1x range across the five salts in the chart above — and it is also the one where being 20% off is immediately obvious on the plate.
Weigh the salt, and brand stops mattering entirely. Our salt converter always shows the gram figure alongside both volumes for this reason: the grams are the answer, the cups are the translation.
The gotchas
Coarse sea salt is a category, not a number. Morton and Diamond Crystal are manufactured to a spec, so their densities are stable. “Sea salt” is whatever the producer’s crystals happen to look like — Maldon-style flakes can be half the density of the coarse sea salt in the chart. The 220 g and 256 g figures are working averages for common supermarket grinds, not guarantees. If your sea salt matters to the dish, weigh it.
Recipes that give salt by weight need no conversion at all. If a recipe says 12 g of salt, use 12 g of anything in the chart. This is why professional recipes increasingly give salt in grams and nothing else.
Scaling multiplies the error. Getting the brand wrong on a single teaspoon is recoverable. Getting it wrong while tripling a recipe is not — the mistake triples with everything else. If you are scaling a recipe, convert the salt to grams first, then scale the grams.
Brines and dry cures are the least forgiving. A brine is nothing but a salt percentage, so a brand swap changes the concentration directly rather than just the seasoning. Work those in grams from the start — our brine calculator does, and the same logic drives the rub weights in the meat smoking calculator.
Table salt is usually iodised. Beyond the density problem, iodised salt can leave a faint metallic edge in delicate dishes and in long ferments. That is a flavour reason to keep kosher salt around, separate from the measuring one.
The one thing to remember
If you take a single number away from this page, make it this: Morton is about 1.7 times Diamond Crystal by volume, not 2. Use ⅗ of the volume, not half.
And if you would rather not do fractions over a hot pan, the salt converter does the arithmetic for you — pick the salt the recipe wanted, pick the salt you own, and it gives you both the volume and the weight. It runs entirely in your browser, like everything else here.
For the neighbouring measuring problems, the cups to grams converter covers flour, sugar and the rest of the pantry, where the same volume-versus-weight argument plays out with slightly lower stakes.