Salt Type Conversion Calculator

Introduction to Salt Type Conversion and Crystal Density

Every culinary salt in this calculator is chemically the same thing: sodium chloride, usually more than 97 percent of the package by mass. What separates a box of table salt from a box of Diamond Crystal kosher salt is not chemistry but geometry. Table salt is produced by evaporating brine under vacuum, which grows small dense cubes that pour freely and pack tightly into a measuring spoon. Kosher salts are grown or rolled into much larger flakes, and those flakes trap air between them. Sea salts sit anywhere along that spectrum depending on how the brine was dried and how finely the harvest was milled.

The practical consequence is that a level teaspoon is a container of fixed volume, roughly 4.93 millilitres, that holds wildly different masses of salt depending on which box you scooped from. A level teaspoon of table salt holds about 6.0 grams. The same spoon of Diamond Crystal kosher salt holds about 2.8 grams. That is a factor of 2.1. If a bread recipe developed with Diamond Crystal says two teaspoons of kosher salt and you measure two teaspoons of table salt, the dough receives roughly 12 grams instead of 5.6 grams, and the loaf is inedibly salty as well as slow to rise.

This calculator converts between five salt types by translating any entry into grams first, then dividing back out by the density of the salt you actually have in the cupboard. It also reports the sodium content of that mass, because the whole reason to preserve grams across a substitution is that sodium, not spoon count, is what your palate and your blood pressure respond to. Each density is editable, so if you own a kitchen scale you can measure your own jar and make the tool exact rather than typical.

How to Use the Salt Type Conversion Calculator

1. Enter the amount the recipe calls for, for example 1.5.
2. Choose the unit the recipe uses: teaspoons, tablespoons, cups, grams, or ounces. Volume units are converted through the density of the recipe salt; mass units are used directly.
3. Select the salt the recipe assumes. If the recipe just says "kosher salt" with no brand, American recipes from Bon Appetit, Serious Eats and the New York Times generally mean Diamond Crystal, while older regional recipes usually mean Morton.
4. Select the salt you actually have. This drives the headline answer and highlights the matching row in the results table.
5. Adjust the density table if you have weighed your own salt. Fill one level teaspoon, level it with a straight edge, weigh it in grams, and type the number in. That single measurement is worth more than any published average.
6. Press Convert. The panel returns the headline swap, a practical spoon breakdown such as "1 Tbsp + 1/4 tsp", the sodium load in milligrams, and a full table of equivalents for all five salt types in teaspoons, tablespoons, and grams.

Press Reset to restore the audited default densities and clear the panel. The Copy result button places a plain-text summary on your clipboard so you can paste it into a recipe note.

The Salt Conversion Formula and Its Density Constants

The conversion is a two-step density calculation. Step one converts whatever you entered into a mass in grams. For a volume entry the amount is first expressed in teaspoons, using 1 tablespoon = 3 teaspoons and 1 US cup = 48 teaspoons, then multiplied by the grams-per-teaspoon figure for the recipe salt:

Step two divides that mass back out by the density of the salt you are substituting in, giving the volume you should measure:

Because the mass cancels, a volume-to-volume swap collapses to a single ratio of the two densities, which is why the same multiplier works for any quantity:

Sodium follows from stoichiometry. Sodium chloride has a molar mass of 58.44 g/mol, of which sodium contributes 22.99 g/mol, so pure salt is 39.34 percent sodium by mass and one gram of salt carries about 393.4 milligrams of sodium:

All of this is the ordinary density relationship , where is mass, is the bulk density of the poured salt, and is the spoon volume. Note that the relevant density is bulk density, which includes the air between crystals, not the 2.17 g/cm³ crystal density of sodium chloride itself. That is exactly why crystal shape matters so much.

Verified Density Table for Common Culinary Salts

The defaults below come from nutrition-label serving weights, which manufacturers must declare to the FDA, and from the USDA FoodData Central record for generic table salt. A nutrition label that says "1/4 tsp (1.2 g)" is a direct statement of density: multiply by four to get grams per teaspoon.

Two figures in that table changed during the most recent audit of this page. Coarse sea salt previously defaulted to 4.0 grams per teaspoon, a number that does not appear on any label we could locate; the declared serving weights we checked cluster between 1.2 g and 1.7 g per quarter teaspoon, so the default is now 5.2 g per teaspoon. Fine sea salt was previously folded into the coarse category and is now a separate selection at 5.6 grams per teaspoon, because finely milled sea salt behaves almost exactly like table salt in a spoon and nothing like a coarse crystal.

Sources and Verification

Every default density on this page traces to a manufacturer nutrition panel or a USDA record. Nothing here is a rounded folk figure.

• USDA FoodData Central, "Salt, table" (FDC ID 173468) — lists 1 tsp = 6.0 g, 1 tbsp = 18.0 g, 1 cup = 292 g, and 38,758 mg sodium per 100 g.
• Morton Iodized Table Salt nutritional facts — serving 1/4 tsp (1.5 g), 590 mg sodium.
• Morton Coarse Kosher Salt nutritional facts — serving 1/4 tsp (1.2 g), 480 mg sodium.
• Diamond Crystal Kosher Salt (Cargill) — serving 1/4 tsp (0.7 g), 280 mg sodium; mirrored in USDA FoodData Central branded record 2571981.
• Morton Fine Sea Salt nutritional facts — serving 1/4 tsp (1.4 g), 560 mg sodium.
• Morton Coarse Sea Salt nutritional facts — serving 1/4 tsp (1.4 g), 580 mg sodium.
• USDA FoodData Central branded search, "coarse sea salt" — declared servings range from 1.2 g to 1.7 g per quarter teaspoon across brands.

The 39.34 percent sodium fraction is derived from standard atomic masses, sodium 22.990 and chlorine 35.453, giving sodium chloride a formula mass of 58.443. USDA lists 38.76 percent for generic iodized table salt rather than 39.34 percent, because commercial table salt also carries anti-caking agents, potassium iodide, dextrose and a little residual moisture. The calculator uses 393.4 mg of sodium per gram of salt, which is within 1.5 percent of the USDA figure and matches the declared label values for the pure kosher and sea salts.

Worked Example: 2 Teaspoons of Table Salt in Diamond Crystal

Suppose a sandwich-loaf recipe calls for 2 teaspoons of table salt and the only salt in your kitchen is Diamond Crystal kosher. Work in grams.

1. Convert to mass with the source density: 2 tsp × 6.0 g/tsp = 12.0 g of salt.
2. Convert that mass to the target volume: 12.0 g ÷ 2.8 g/tsp ≈ 4.29 tsp of Diamond Crystal.
3. Express it in spoons you actually own: 4.29 tsp is 1 tablespoon plus about 1 1/4 teaspoons.
4. Check the sodium: 12.0 g × 393.4 mg/g ≈ 4,720 mg of sodium for the whole loaf, unchanged by the swap. That is the entire point of the conversion.

Run it the other way and the danger becomes obvious. A recipe written for 2 teaspoons of Diamond Crystal means 5.6 g. If you reach for table salt and measure 2 teaspoons anyway, you have added 12.0 g, which is 2.1 times the intended sodium. In a brine or a cure that error is a food-safety issue, not just a seasoning issue. The correct table-salt measure is 5.6 ÷ 6.0 ≈ 0.93 tsp, or a scant teaspoon.

The same arithmetic explains the two rules of thumb you will see in cookbooks. Doubling the volume when moving from table salt to Diamond Crystal is a decent approximation of the true 2.14 ratio. Multiplying by 1.5 when moving from Morton kosher to Diamond Crystal approximates the true 1.71 ratio, and it is the rule most likely to leave a dish under-seasoned.

Reading and Applying the Conversion Results

The results panel returns four things. The headline gives the volume of your target salt in teaspoons together with a rounded spoon breakdown, because nobody owns a 4.29-teaspoon measure. The gram figure is the number to trust if you have a scale, and it is identical for every row of the table. The sodium figure lets you compare the recipe against dietary targets; the FDA daily value used on nutrition labels is 2,300 mg of sodium. Finally the table lists all five salt types at once, so you can see the whole family of equivalents and pick whichever box you happen to open.

Some practical notes on measuring. Level the spoon with the back of a knife rather than shaking it, because tapping the spoon settles coarse crystals and can add 10 to 15 percent. Do not scoop directly from the box with the measuring spoon for coarse salts, since scooping compacts them; spoon the salt in loosely instead. If a conversion returns an awkward figure such as 3.4 teaspoons, round toward the smaller amount and taste, since salt can be added later but not removed.

For brines, cures, and bread the gram column is the only column worth reading. Baker's percentage formulas already express salt as a percentage of flour weight, typically 1.8 to 2.2 percent, and the number is meaningless unless you weigh. For soups, braises and roasted vegetables the volume columns are perfectly adequate, because you will taste and adjust before serving anyway.

Why the Densities Differ So Much Between Brands

Table salt is made by vacuum-evaporating purified brine, which nucleates small, regular cubic crystals in a narrow size band. Those cubes tessellate well and leave little void space, so bulk density approaches 1.2 g/cm³. Anti-caking agents such as calcium silicate keep the grains flowing freely and, if anything, help them pack.

Morton's kosher salt starts from similar cubes and then passes them through rollers, which flatten the crystals into flakes. Flakes bridge against each other and trap air, dropping the bulk density to about 0.97 g/cm³. Diamond Crystal uses the Alberger process, in which brine is evaporated in an open pan so that crystals grow as hollow, inverted pyramids. Those pyramids are mostly air, and the bulk density falls to roughly 0.57 g/cm³, which is why the same spoon holds less than half the mass.

Sea salts vary because harvesting and milling vary. Finely milled sea salt is close to table salt. Grinder and coarse sea salts hold larger irregular grains with more void space, and hand-harvested flake salts such as fleur de sel or Maldon are lighter still and often too irregular to measure by spoon at all. Residual moisture also matters: a damp coarse sea salt weighs more per spoon but contains proportionally less sodium chloride, which pushes the sodium estimate slightly high.

Limitations, Assumptions, and When to Reach for a Scale

This calculator is a practical kitchen aid, and the following limitations are real:

• Brand variability inside a category. "Coarse sea salt" is not a specification. Declared serving weights across brands run from 1.2 g to 1.7 g per quarter teaspoon, a 40 percent spread. Override that field first if precision matters.
• Label rounding. Nutrition panels round serving weights to a tenth of a gram, so a declared 0.7 g could be anywhere from 0.65 g to 0.75 g. That is up to ±7 percent baked into the Diamond Crystal figure before you touch a spoon.
• Packing and technique. The defaults assume a level, loosely filled spoon. Scooping, tapping, or heaping a coarse salt can change the mass by 10 to 20 percent, which is larger than most of the differences the calculator is resolving.
• Humidity and clumping. Salt is hygroscopic. A jar of coarse sea salt left open in a humid kitchen gains water, weighs more per spoon, and delivers less sodium than the calculation implies.
• Flake and finishing salts are excluded. Maldon, fleur de sel, smoked salts and seasoned blends are not modelled. Flake salts are meant to be pinched, not spooned, and blends contain non-salt ingredients.
• Sodium is estimated, not measured. The 393.4 mg per gram constant assumes essentially pure sodium chloride. Low-sodium substitutes built on potassium chloride, and seasoned salts, will not match.
• Not a medical tool. If you are managing sodium for a clinical reason, use nutrition labels and the advice of a clinician or dietitian rather than a volume conversion.

The assumption underneath all of it is that you want to preserve total sodium chloride mass across the substitution. That is right for seasoning, brining and baking. It is not right for finishing, where the point of a flake salt is the crunch and the burst of salinity on the tongue rather than the total mass, and a gram-for-gram substitution of table salt will taste harsher and flatter.

Frequently Asked Questions About Salt Substitutions

Use this tool as a practical guide rather than an absolute rule. When in doubt, err on the low side and adjust the seasoning to taste, because salt can always be added and never removed.