This curing salt calculator does one narrow job: it turns a meat weight and a curing salt rate into the mass of Prague Powder you would weigh out, the mass of sodium nitrite that represents, and the resulting ingoing concentration in parts per million. It then shows that concentration next to the ingoing limit the United States Department of Agriculture's Food Safety and Inspection Service publishes for the curing method you selected. It is arithmetic, and arithmetic is not the part of curing that keeps anyone safe.
Arb Digital builds free reference tools, and this is one of the few where the framing matters more than the maths. Sodium nitrite is toxic in small quantities. Too little of it in a cured, low-oxygen, slowly-processed meat leaves room for Clostridium botulinum; too much of it is an acute poison, and sodium nitrite poisoning is a documented cause of death. A calculator sits in the middle of that range and can tell you what a ratio works out to. It cannot tell you whether a batch of food is safe, and this page never will.
What This Curing Salt Calculator Does
Enter the weight of trimmed meat, the weight of any brine water, and the curing salt rate your recipe specifies in grams per kilogram. The calculator multiplies the rate by the total weight to get the curing salt mass, takes 6.25% of that mass as sodium nitrite — the published nitrite fraction of both Prague Powder #1 and Prague Powder #2 — and divides the result back into the total weight to express it in parts per million. Plain salt and sugar are calculated separately as percentages of the same total, because they are seasoning ingredients and have nothing to do with the nitrite figure.
The comparison bar puts your calculated ppm alongside the limit published for the method you chose. That comparison is descriptive. A result under the published limit is not a statement that the batch is safe, and this tool issues no verdict of any kind.
The cure-duration line multiplies the thickest measurement of the cut by a days-per-inch figure that you supply from your recipe. The page publishes no cure-time table of its own, because penetration depends on temperature, salt concentration, muscle structure and geometry — none of which a single multiplier captures.
How to Use It
- Choose the product your recipe names. Prague Powder #1 and Prague Powder #2 are different products for different applications and must not be swapped for one another.
- Weigh the meat. Trim first, then weigh, and enter that figure. If you are wet curing, weigh the water too and enter it in the brine field.
- Enter the rate from your tested recipe in grams of curing salt per kilogram of total weight. If your recipe gives a ratio in ounces per hundredweight or teaspoons per pound, convert it rather than guessing — the grams to ounces converter and the cooking measurement converter handle that step.
- Select the curing method so the correct published ingoing limit is displayed for comparison.
- Read the ppm figure and the comparison, then take both back to your recipe and to a food safety authority. The number is an input to that conversation, not a conclusion.
The Formula and Where Each Figure Comes From
The arithmetic is a single chain. Curing salt mass equals rate multiplied by total weight in kilograms. Sodium nitrite mass equals curing salt mass multiplied by 0.0625, because Prague Powder #1 is 6.25% sodium nitrite with the balance sodium chloride plus an anti-caking agent and a colourant that gives the product its pink appearance. Ingoing concentration in parts per million equals nitrite mass divided by total mass, multiplied by one million.
The single most widely published cross-check in North American curing is 4 ounces of Prague Powder #1 per 100 pounds of meat, which is stated to deliver 156 ppm sodium nitrite. Run it through: 4 ounces is 113.398 grams; 6.25% of that is 7.087 grams of sodium nitrite; 100 pounds is 45,359 grams; 7.087 divided by 45,359 is 0.00015625, or 156.25 ppm. The ratio reproduces exactly. Metrically that is 2.5 grams of curing salt per kilogram, the default this page ships with — and it is a default, not advice.
The ingoing limits shown come from the United States regulation at 9 CFR 424.21(c), administered by USDA FSIS, which sets maximum ingoing sodium nitrite by curing method: comminuted products 156 ppm, immersion cured 200 ppm, massaged or pumped 200 ppm, and dry cured 625 ppm, with a lower figure of 120 ppm for pumped bacon and no sodium nitrate permitted in bacon at all. FSIS's own consumer page, Additives in Meat and Poultry Products, explains that these caps were set precisely because excess nitrite or nitrate is toxic, and that high concentrations can induce methaemoglobinaemia, a particular risk for infants and children. If you are outside the United States, your own competent authority publishes its own figures and yours are the ones that apply.
Prague Powder #1 and Prague Powder #2 Are Not Alternatives
Prague Powder #1 contains sodium nitrite and no nitrate. It is for short cures that end in cooking or refrigerated storage — bacon, brined poultry, corned beef, cooked sausages, hot-smoked products. The nitrite is available immediately and is largely consumed during the cure.
Prague Powder #2 contains the same 6.25% sodium nitrite plus roughly 4% sodium nitrate. The nitrate is a slow reservoir: over weeks it converts to nitrite, which is why #2 is named for long-aged, uncooked dry-cured goods such as salami, coppa and country hams. Using #2 where a recipe calls for #1 leaves residual nitrate in a product never designed to carry it; using #1 where #2 is called for leaves a long-aged product without nitrite protection in its later weeks.
The Mississippi State University Extension Service publication Curing Pork Products at Home is worth reading in full before any home cure. It states plainly that "too much nitrate and nitrite can be toxic", gives its own cure formulations and application rates, and declines to promote home aging of dry-cured meats in the southeastern United States at all, because the local climate can make aged product unsafe.
Why Curing Salt Must Be Weighed, Never Measured by Volume
A teaspoon is a volume, and the mass of curing salt that fits in one depends on crystal size, settling, humidity and how level the spoon is. Extension guidance is consistent: use weights rather than volumes for curing salt, because volume measurements are approximations. A 2 kg batch at 2.5 g/kg needs 5.00 g of curing salt containing 0.31 g of sodium nitrite. A spoon that is 30% generous puts a third more nitrite into food than the recipe intended.
Weigh curing salt on a scale accurate to 0.1 g. A kitchen scale that reads to the nearest gram is not adequate for small batches, because a single gram of error on a 5 g dose is a 20% error in nitrite. Weigh into a separate, clearly labelled container. Never keep curing salt in an unlabelled jar, never store it next to table salt, and keep it well away from children — it is pink for exactly this reason, and the colour is a warning, not decoration.
Curing salt is never a substitute for table salt. It is not "salt with something added" in any everyday sense; it is a dilute delivery system for a toxic compound, and the salt is the carrier. If you want to think about the sodium in the plain salt portion of a cure, the salt to sodium converter handles that conversion — it deals only with sodium chloride and has nothing to say about nitrite, which is the whole reason this page exists as a separate tool.
The Boundary Between This Tool and the Brine Calculator
Our brine calculator works out salt and sugar by percentage for a flavour-and-moisture brine — the kind used on a chicken before roasting, where the goal is seasoning and water retention. There is no nitrite in it and no preservation claim attached to it. This page is the other thing entirely: nitrite-based curing, where the additive inhibits a specific organism over a specific timeframe and where a regulatory ingoing limit exists. If your recipe does not name a curing salt, you want the brine calculator, not this one.
What the Arithmetic Cannot Tell You
Nitrite concentration is one variable among several, and it is the only one on this page. Curing safety is governed by the tested recipe, by temperature control throughout the cure, by time, by water activity as the product dries, by pH, and by the condition of the meat when it went in. A correct ppm figure in a cure held at the wrong temperature is not a safe product. A correct ppm figure applied unevenly — a rub that never reached the centre of a thick cut — is not a safe product either.
Nor does the calculation know what happens to the nitrite after you add it. Ingoing nitrite is not residual nitrite; the compound is consumed as it reacts with myoglobin and with the meat's own chemistry, and residual levels at the point of eating are substantially lower. Regulations are written against the ingoing number because that is the one a processor controls, which is why this tool reports ingoing nitrite and nothing else.
Botulism is the reason nitrite is in cured meat at all. FSIS maintains a dedicated page on Clostridium botulinum and botulism, and anyone curing at home should understand the organism before choosing a recipe rather than after.
Temperature, Time and the Part a Calculator Never Sees
Cure penetration is diffusion, and diffusion is slow, temperature-dependent and geometry-dependent. A flat belly of uniform thickness cures far more predictably than a bone-in leg with a thick end and a thin end. Recipes that give days per inch compress all of that into one number for one class of product at one holding temperature, which is why the figure belongs to the recipe rather than to a general-purpose calculator. Cooking temperature is a separate question again, and one this tool has no view on: the steak cooking time calculator and the turkey cooking time calculator deal with heat and time, and neither of them, nor this page, sets a safe internal temperature. That comes from your food safety authority.
Arb Digital publishes a large library of free calculators and converters, built to show their working and name their sources. Browse the hub, or get in touch if something is missing or wrong.
Browse Free Tools Contact Arb DigitalCommon Mistakes to Avoid
- Measuring curing salt by spoon. Volume is an approximation and nitrite is not a place for approximations. Weigh it, on a scale that reads to 0.1 g.
- Substituting Prague Powder #2 for #1 or the reverse. They carry different chemistry for different timescales and are not interchangeable in either direction.
- Forgetting the brine water in the total weight. In a wet cure, the nitrite is distributed through meat and water together; leaving the water out of the total overstates the concentration you calculated and understates what you should have added.
- Treating a figure under the published limit as a safety verdict. The limit is a maximum set by regulation. Being below it says nothing about temperature control, cure time, or whether the recipe was tested.
- Storing curing salt loose or unlabelled. It looks like seasoning, it is not seasoning, and it needs to be kept where nobody can mistake it — well out of reach of children.
Related Free Tools From Arb Digital
For a plain flavour brine with no curing agent, use the brine calculator. For sodium chloride arithmetic on its own, the salt to sodium converter is the right page. Weight conversions are handled by the grams to ounces converter and the cooking measurement converter, and if you are planning quantities for a cook-out rather than a cure, the BBQ food calculator works back from portions to raw weight. The full free online tools hub lists everything else.
Frequently Asked Questions
Because Prague Powder #1 is 6.25 percent sodium nitrite, 2.5 grams of it per kilogram of total weight works out at approximately 156 ppm ingoing sodium nitrite. That is the metric equivalent of the widely published ratio of 4 ounces per 100 pounds of meat, which the arithmetic reproduces at 156.25 ppm.
Both contain 6.25 percent sodium nitrite. Prague Powder #2 also contains roughly 4 percent sodium nitrate, which converts slowly to nitrite over weeks, so it is the product named for long-aged uncooked dry cures such as salami and country ham. Prague Powder #1 is for shorter cures that end in cooking or refrigeration. Your recipe names one of them and they are not interchangeable.
In the United States, 9 CFR 424.21(c), administered by USDA FSIS, sets maximum ingoing sodium nitrite by curing method: 156 ppm for comminuted products, 200 ppm for immersion cured and for massaged or pumped, and 625 ppm for dry cured, with 120 ppm for pumped bacon. Other countries publish their own figures and those are the ones that apply where you are.
No. Extension guidance is consistent that curing salt should be weighed rather than measured by volume, because volume measurements are approximations and the doses involved are small. Use a scale accurate to 0.1 grams. On a five gram dose, one gram of error is a twenty percent error in nitrite.
Sodium nitrite is toxic in small quantities and sodium nitrite poisoning is a documented cause of death. Curing salt must never be substituted for table salt, must be weighed rather than spooned, must be stored labelled and separate from ordinary seasonings, and must be kept away from children. The pink colour exists as a warning.
No, and this tool never says so. The published limit is a regulatory maximum on one ingredient. Safety comes from following a tested recipe from a food safety authority, holding the correct temperature throughout the cure, giving it the correct time, and handling the meat properly. Arithmetic alone does not make food safe.
This page publishes no cure-time rule. Cure penetration depends on temperature, salt concentration, the geometry and thickness of the cut, and whether the piece is pumped. The days-per-inch figure in the calculator is a field you fill in from your own tested recipe, and the default value in it is a placeholder rather than a recommendation.
Ingoing nitrite is what you add. Nitrite is then consumed as it reacts with myoglobin and the wider chemistry of the meat, so the residual level at the point of eating is substantially lower. Regulations are written against the ingoing figure because that is the quantity a processor controls, and it is the only figure this calculator produces.
This calculator is a reference aid and is not food safety guidance. Sodium nitrite is toxic in small quantities. Follow a tested recipe from a food safety authority such as USDA FSIS or your national equivalent, weigh curing salt on a scale accurate to 0.1 g, control temperature and time throughout the cure, and store curing salt labelled and away from children. This page never states that a batch of food is safe.
