About

Miscalculating curing salt turns a craft project into a health hazard. Sodium nitrite is toxic above 200 ppm ingoing concentration, yet too little invites Clostridium botulinum growth. This calculator applies USDA FSIS guidelines and the equilibrium curing method to compute precise quantities of salt, Prague Powder #1 (containing 6.25% sodium nitrite by weight), sugar, and water for both dry and immersion brines. Input your meat weight and thickness; the tool returns gram-accurate ingredient amounts and estimated curing duration based on the Marianski approximation of 7 days/inch for dry cure.

The equilibrium method differs from excess-salt methods: you calculate ingredients as a fixed percentage of raw meat mass, so the finished product cannot become over-salted regardless of curing time. This tool assumes ambient refrigeration at 2 - 4 °C (36 - 39 °F). Results are approximations. Whole-muscle geometry, connective tissue density, and fat-cap thickness introduce real-world variance. Always verify nitrite concentration against your local food-safety authority before consumption.

Formulas

The equilibrium method calculates each ingredient as a percentage of the raw meat weight M. For a target salt percentage S:

W_salt = M × S100

Prague Powder #1 contains 6.25% sodium nitrite. To achieve target ingoing nitrite concentration C in ppm:

W_PP1 = C × M62500

where M is in grams and result W_PP1 is in grams. The denominator 62500 derives from 1000000 ppm × 0.0625 nitrite fraction.

For brine curing, water volume V_w is set as a fraction of meat weight, and salt is dissolved into it:

V_w = M × R_water

W_{brine salt} = V_w × S_brine100

Estimated curing time uses thickness T in inches:

D_dry = T × 7 days

D_brine = T × 3.5 days

Where: M = raw meat weight, S = salt percentage, C = target nitrite ppm, R_water = water-to-meat ratio, T = meat thickness, D = curing duration.

Reference Data

Product	Cut	Method	Salt %	Cure #1 ppm	Sugar %	Time days/inch	Notes
Back Bacon	Pork loin	Dry EQ	2.5	156	1.0	7	Canadian style, lean
Streaky Bacon	Pork belly	Dry EQ	2.75	156	1.5	7	American style
Pancetta	Pork belly	Dry EQ	3.0	156	0.5	7	Rolled, air-dried after cure
Guanciale	Pork jowl	Dry EQ	3.0	0	0	7	No nitrite, black pepper heavy
Corned Beef	Beef brisket	Brine	5.0	156	2.0	3.5	Immersion brine, pickling spice
Pastrami	Beef navel/brisket	Brine	5.0	156	2.5	3.5	Brined then smoked
Bresaola	Beef eye of round	Dry EQ	3.0	156	0.75	7	Air-dried 30-40% weight loss
Duck Prosciutto	Duck breast	Dry excess	2.5	0	0	1	24h salt, then air-dry
Lonza	Pork loin	Dry EQ	3.0	156	0.5	7	Italian cured loin
Lardo	Pork fatback	Dry excess	3.0	0	0	14	Pure fat, herb-rubbed, 6 mo cure
Coppa	Pork neck/collar	Dry EQ	2.75	156	0.25	7	Cased and air-dried
Buckboard Bacon	Pork shoulder	Dry EQ	2.5	156	1.5	7	Budget bacon alternative
Cottage Bacon	Pork shoulder butt	Dry EQ	2.5	156	1.0	7	Sliced thin, pan-fried
Speck	Pork leg	Dry EQ	3.0	150	0.5	7	Juniper, cold-smoked, Tyrolean
Jowl Bacon	Pork jowl	Dry EQ	2.5	156	1.0	7	Rich, fatty, Southern US style

Frequently Asked Questions

USDA FSIS regulation 9 CFR 424.21 caps sodium nitrite at 156 ppm for immersion-cured products and 200 ppm for dry-cured products. These limits were established based on toxicology studies showing that concentrations above 200 ppm provide no additional antimicrobial benefit against C. botulinum while increasing health risk. This calculator defaults to 156 ppm as the safer universal ceiling.

The calculator outputs weights in grams, so salt type does not matter when weighing. Salt is salt by weight. However, if you measure by volume, Morton Kosher Salt is approximately 1.5× the volume of table salt for the same weight, and Diamond Crystal Kosher is approximately 2× the volume. Always weigh curing ingredients on a scale accurate to 0.1 g.

Use the thickest point of the cut for the thickness input. The thinnest areas will cure faster but will not become dangerously over-salted in an equilibrium cure because the total salt is pre-calculated as a percentage of mass. The thick end governs minimum safe curing time. For cuts with extreme variation (e.g., a tapered brisket point), consider separating the flat from the point and curing independently.

Prague Powder #1 contains 6.25% sodium nitrite and 93.75% table salt. It is used for short cures (days to weeks) and products that will be cooked or smoked. Prague Powder #2 contains 6.25% sodium nitrite plus 4% sodium nitrate and 89.75% salt. The nitrate slowly converts to nitrite over months, making PP#2 suitable for long air-dried products like bresaola or salami. This calculator computes PP#1 by default. For PP#2, the nitrite calculation remains identical; the additional nitrate serves as a time-release reservoir and does not change the initial ppm calculation.

Yes. All time estimates assume refrigeration at 2-4 °C (36-39 °F). At higher temperatures, salt diffusion accelerates but so does bacterial growth, creating a food-safety risk. Below 0 °C, diffusion slows dramatically and the meat may partially freeze, preventing proper curing. Never cure at room temperature unless you are performing a traditional excess-salt method under controlled humidity and the product will be air-dried to a water activity below 0.85.

In an excess-salt (or "salt box") method, meat sits in far more salt than it can absorb, and timing is critical to prevent a brick-like result. In equilibrium curing, you apply only the exact amount of salt the final product should contain - typically 2-3% of meat weight. Given enough time, the salt distributes evenly throughout the muscle via osmotic diffusion. Leaving it an extra day or two causes no harm because there is no excess salt to absorb.