{
  "source": "https://brewgravity.com",
  "license": "CC BY-NC 4.0 — https://creativecommons.org/licenses/by-nc/4.0/",
  "generated": "2026-09-19",
  "count": 15,
  "calculators": [
    {
      "slug": "abv",
      "url": "https://brewgravity.com/calculators/abv",
      "name": "ABV Calculator",
      "query": "What is my ABV from OG and FG?",
      "formula": "ABV = (76.08 × (OG - FG) / (1.775 - OG)) × (FG / 0.794)",
      "inputs": [
        {
          "id": "og",
          "label": "Original gravity (OG)",
          "type": "number",
          "default": "1.055",
          "min": "1",
          "step": "0.001"
        },
        {
          "id": "fg",
          "label": "Final gravity (FG)",
          "type": "number",
          "default": "1.012",
          "min": "0.98",
          "step": "0.001"
        }
      ],
      "outputs": [
        {
          "id": "abv",
          "label": "ABV"
        },
        {
          "id": "abw",
          "label": "ABW"
        },
        {
          "id": "att",
          "label": "Apparent attenuation"
        },
        {
          "id": "cal",
          "label": "Calories / 12 oz"
        }
      ]
    },
    {
      "slug": "ibu",
      "url": "https://brewgravity.com/calculators/ibu",
      "name": "IBU Calculator",
      "query": "How many IBUs does this hop addition contribute?",
      "formula": "IBU = (g × alpha × utilisation) / (volume × 10); utilisation via Tinseth",
      "inputs": [
        {
          "id": "grams",
          "label": "Hop weight (g)",
          "type": "number",
          "default": "28",
          "min": "0",
          "step": "1"
        },
        {
          "id": "alpha",
          "label": "Alpha acid (%)",
          "type": "number",
          "default": "12",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "time",
          "label": "Boil time (min)",
          "type": "number",
          "default": "60",
          "min": "0",
          "step": "1"
        },
        {
          "id": "og",
          "label": "Boil gravity",
          "type": "number",
          "default": "1.055",
          "min": "1",
          "step": "0.001"
        },
        {
          "id": "volume",
          "label": "Batch volume (L)",
          "type": "number",
          "default": "19",
          "min": "0.1",
          "step": "0.5"
        },
        {
          "id": "form",
          "label": "Hop form",
          "type": "select",
          "default": "pellet",
          "options": [
            "pellet",
            "plug",
            "leaf"
          ]
        },
        {
          "id": "use",
          "label": "Addition type",
          "type": "select",
          "default": "boil",
          "options": [
            "boil",
            "first_wort",
            "whirlpool",
            "dry_hop"
          ]
        }
      ],
      "outputs": [
        {
          "id": "ibu",
          "label": "IBU"
        },
        {
          "id": "util",
          "label": "Utilisation"
        }
      ]
    },
    {
      "slug": "beer-color-srm",
      "url": "https://brewgravity.com/calculators/beer-color-srm",
      "name": "Beer Color Calculator (SRM & EBC)",
      "query": "What color will my beer be?",
      "formula": "SRM = 1.4922 × MCU^0.6859; MCU = (color × lbs) / gal",
      "inputs": [
        {
          "id": "weight",
          "label": "Malt weight (kg)",
          "type": "number",
          "default": "5",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "color",
          "label": "Malt color (°L / SRM)",
          "type": "number",
          "default": "4",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "volume",
          "label": "Batch volume (L)",
          "type": "number",
          "default": "19",
          "min": "0.1",
          "step": "0.5"
        }
      ],
      "outputs": [
        {
          "id": "srm",
          "label": "SRM"
        },
        {
          "id": "ebc",
          "label": "EBC"
        },
        {
          "id": "mcu",
          "label": "MCU"
        },
        {
          "id": "swatch",
          "label": "Color"
        }
      ]
    },
    {
      "slug": "priming-sugar",
      "url": "https://brewgravity.com/calculators/priming-sugar",
      "name": "Priming Sugar Calculator",
      "query": "How much priming sugar do I need?",
      "formula": "sugar_g = (target_CO2 - residual_CO2) × volume × sugar_factor",
      "inputs": [
        {
          "id": "volume",
          "label": "Beer volume (L)",
          "type": "number",
          "default": "19",
          "min": "0.1",
          "step": "0.5"
        },
        {
          "id": "temp",
          "label": "Beer temperature (°C)",
          "type": "number",
          "default": "20",
          "step": "0.5"
        },
        {
          "id": "co2",
          "label": "Target CO₂ volumes",
          "type": "number",
          "default": "2.4",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "sugar",
          "label": "Priming sugar",
          "type": "select",
          "default": "corn_sugar",
          "options": [
            "corn_sugar",
            "table_sugar",
            "dme",
            "honey"
          ]
        }
      ],
      "outputs": [
        {
          "id": "grams",
          "label": "Sugar needed"
        },
        {
          "id": "oz",
          "label": "In ounces"
        },
        {
          "id": "residual",
          "label": "CO₂ already in beer"
        }
      ]
    },
    {
      "slug": "strike-water",
      "url": "https://brewgravity.com/calculators/strike-water",
      "name": "Strike Water Calculator",
      "query": "What temperature should my strike water be?",
      "formula": "T_strike = (0.2 / ratio) × (T_target - T_grain) + T_target",
      "inputs": [
        {
          "id": "grain",
          "label": "Grain weight (kg)",
          "type": "number",
          "default": "5",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "target",
          "label": "Target mash temp (°C)",
          "type": "number",
          "default": "66",
          "step": "0.5"
        },
        {
          "id": "grainTemp",
          "label": "Grain temperature (°C)",
          "type": "number",
          "default": "20",
          "step": "0.5"
        },
        {
          "id": "ratio",
          "label": "Water-to-grain ratio (L/kg)",
          "type": "number",
          "default": "3",
          "min": "0.5",
          "step": "0.1"
        }
      ],
      "outputs": [
        {
          "id": "strike",
          "label": "Strike temp"
        },
        {
          "id": "strikeF",
          "label": "Strike temp (°F)"
        },
        {
          "id": "water",
          "label": "Strike water"
        },
        {
          "id": "absorb",
          "label": "Lost to grain"
        }
      ]
    },
    {
      "slug": "brewhouse-efficiency",
      "url": "https://brewgravity.com/calculators/brewhouse-efficiency",
      "name": "Brewhouse Efficiency Calculator",
      "query": "What is my brewhouse efficiency?",
      "formula": "efficiency = actual_points / potential_points",
      "inputs": [
        {
          "id": "og",
          "label": "Measured OG",
          "type": "number",
          "default": "1.052",
          "min": "1",
          "step": "0.001"
        },
        {
          "id": "volume",
          "label": "Batch volume (L)",
          "type": "number",
          "default": "19",
          "min": "0.1",
          "step": "0.5"
        },
        {
          "id": "grain",
          "label": "Total grain (kg)",
          "type": "number",
          "default": "5",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "ppg",
          "label": "Average malt yield (PPG)",
          "type": "number",
          "default": "36",
          "min": "1",
          "step": "0.5"
        }
      ],
      "outputs": [
        {
          "id": "eff",
          "label": "Brewhouse efficiency"
        },
        {
          "id": "actual",
          "label": "Points extracted"
        },
        {
          "id": "max",
          "label": "Points available"
        }
      ]
    },
    {
      "slug": "refractometer",
      "url": "https://brewgravity.com/calculators/refractometer",
      "name": "Refractometer Correction Calculator",
      "query": "What is my corrected FG from a refractometer reading?",
      "formula": "FG via Bonham WRI correction: brixWriToSG(correctedBrix, OG)",
      "inputs": [
        {
          "id": "og",
          "label": "Original gravity (SG)",
          "type": "number",
          "default": "1.055",
          "min": "1",
          "step": "0.001"
        },
        {
          "id": "brix",
          "label": "Current refractometer reading (°Bx)",
          "type": "number",
          "default": "7.5",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "wcf",
          "label": "Wort correction factor",
          "type": "number",
          "default": "1.04",
          "min": "0.9",
          "step": "0.01"
        }
      ],
      "outputs": [
        {
          "id": "fg",
          "label": "Corrected FG"
        },
        {
          "id": "abv",
          "label": "ABV"
        },
        {
          "id": "att",
          "label": "Apparent attenuation"
        }
      ]
    },
    {
      "slug": "brix-to-gravity",
      "url": "https://brewgravity.com/calculators/brix-to-gravity",
      "name": "Brix to Gravity Converter",
      "query": "How do I convert between Brix and specific gravity?",
      "formula": "SG = 1 + plato / (258.6 - 0.879 × plato × 227.1 / 258.2)",
      "inputs": [
        {
          "id": "dir",
          "label": "Convert",
          "type": "select",
          "default": "brix",
          "options": [
            "brix",
            "sg"
          ]
        },
        {
          "id": "brix",
          "label": "Brix / Plato (°)",
          "type": "number",
          "default": "13.5",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "sg",
          "label": "Specific gravity",
          "type": "number",
          "default": "1.055",
          "min": "1",
          "step": "0.001"
        }
      ],
      "outputs": [
        {
          "id": "sgOut",
          "label": "Specific gravity"
        },
        {
          "id": "brixOut",
          "label": "Brix / Plato"
        },
        {
          "id": "points",
          "label": "Gravity points"
        }
      ]
    },
    {
      "slug": "keg-carbonation",
      "url": "https://brewgravity.com/calculators/keg-carbonation",
      "name": "Keg Carbonation Calculator",
      "query": "What CO₂ pressure should I set for my keg?",
      "formula": "PSI from Henry's law: f(CO2_volumes, temp_C)",
      "inputs": [
        {
          "id": "temp",
          "label": "Keg temperature (°C)",
          "type": "number",
          "default": "4",
          "step": "0.5"
        },
        {
          "id": "co2",
          "label": "Target CO₂ volumes",
          "type": "number",
          "default": "2.4",
          "min": "0",
          "step": "0.1"
        }
      ],
      "outputs": [
        {
          "id": "psi",
          "label": "Regulator pressure"
        },
        {
          "id": "bar",
          "label": "In bar"
        },
        {
          "id": "tempF",
          "label": "Keg temperature"
        }
      ]
    },
    {
      "slug": "final-gravity",
      "url": "https://brewgravity.com/calculators/final-gravity",
      "name": "Final Gravity Calculator",
      "query": "What final gravity should I expect?",
      "formula": "FG = 1 + (OG - 1) × (1 - attenuation / 100)",
      "inputs": [
        {
          "id": "og",
          "label": "Original gravity (OG)",
          "type": "number",
          "default": "1.055",
          "min": "1",
          "step": "0.001"
        },
        {
          "id": "att",
          "label": "Yeast apparent attenuation (%)",
          "type": "number",
          "default": "75",
          "min": "0",
          "max": "100",
          "step": "1"
        }
      ],
      "outputs": [
        {
          "id": "fg",
          "label": "Predicted FG"
        },
        {
          "id": "abv",
          "label": "Predicted ABV"
        },
        {
          "id": "range",
          "label": "Likely range"
        }
      ]
    },
    {
      "slug": "yeast-pitch-rate",
      "url": "https://brewgravity.com/calculators/yeast-pitch-rate",
      "name": "Yeast Pitch Rate Calculator",
      "query": "How much yeast do I need to pitch?",
      "formula": "cells = pitch_rate × volume_mL × degrees_plato",
      "inputs": [
        {
          "id": "og",
          "label": "Original gravity (OG)",
          "type": "number",
          "default": "1.055",
          "min": "1",
          "step": "0.001"
        },
        {
          "id": "volume",
          "label": "Batch volume (L)",
          "type": "number",
          "default": "19",
          "min": "0.1",
          "step": "0.5"
        },
        {
          "id": "type",
          "label": "Beer type",
          "type": "select",
          "default": "ale",
          "options": [
            "ale",
            "lager",
            "hybrid"
          ]
        }
      ],
      "outputs": [
        {
          "id": "cells",
          "label": "Cells needed"
        },
        {
          "id": "packs",
          "label": "Liquid yeast packs"
        },
        {
          "id": "dryG",
          "label": "Dry yeast"
        }
      ]
    },
    {
      "slug": "hydrometer-correction",
      "url": "https://brewgravity.com/calculators/hydrometer-correction",
      "name": "Hydrometer Temperature Correction",
      "query": "What is my corrected hydrometer reading at this temperature?",
      "formula": "SG_corrected = reading × poly(T_sample) / poly(T_cal)",
      "inputs": [
        {
          "id": "reading",
          "label": "Hydrometer reading (SG)",
          "type": "number",
          "default": "1.050",
          "min": "0.98",
          "step": "0.001"
        },
        {
          "id": "temp",
          "label": "Sample temperature (°C)",
          "type": "number",
          "default": "30",
          "step": "0.5"
        },
        {
          "id": "cal",
          "label": "Calibration temperature (°C)",
          "type": "number",
          "default": "20",
          "step": "0.5"
        }
      ],
      "outputs": [
        {
          "id": "corrected",
          "label": "Corrected SG"
        },
        {
          "id": "plato",
          "label": "Corrected °Plato"
        },
        {
          "id": "delta",
          "label": "Correction"
        }
      ]
    },
    {
      "slug": "water-volume",
      "url": "https://brewgravity.com/calculators/water-volume",
      "name": "Water Volume Calculator",
      "query": "How much water do I need for this brew?",
      "formula": "total = mash_water + sparge_water; mash = grain_kg × ratio",
      "inputs": [
        {
          "id": "batch",
          "label": "Target batch volume (L)",
          "type": "number",
          "default": "19",
          "min": "0.1",
          "step": "0.5"
        },
        {
          "id": "grain",
          "label": "Total grain (kg)",
          "type": "number",
          "default": "5",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "boil",
          "label": "Boil time (min)",
          "type": "number",
          "default": "60",
          "min": "0",
          "step": "5"
        },
        {
          "id": "boiloff",
          "label": "Boiloff rate (L/hr)",
          "type": "number",
          "default": "3.8",
          "min": "0",
          "step": "0.1"
        },
        {
          "id": "mashType",
          "label": "Mash type",
          "type": "select",
          "default": "sparge",
          "options": [
            "sparge",
            "full_volume"
          ]
        }
      ],
      "outputs": [
        {
          "id": "total",
          "label": "Total water needed"
        },
        {
          "id": "mash",
          "label": "Mash water"
        },
        {
          "id": "ratio",
          "label": "Mash ratio"
        },
        {
          "id": "sparge",
          "label": "Sparge water"
        },
        {
          "id": "preboil",
          "label": "Pre-boil volume"
        },
        {
          "id": "absorb",
          "label": "Grain absorption"
        },
        {
          "id": "boiloffOut",
          "label": "Boiloff"
        }
      ]
    },
    {
      "slug": "carbonation-time",
      "url": "https://brewgravity.com/calculators/carbonation-time",
      "name": "Force Carbonation Time Calculator",
      "query": "How long will force carbonation take?",
      "formula": "days ≈ −ln(1 − fraction) / k; k from pressure and temperature",
      "inputs": [
        {
          "id": "psi",
          "label": "Applied pressure (psi)",
          "type": "number",
          "default": "12",
          "min": "0",
          "step": "0.5"
        },
        {
          "id": "temp",
          "label": "Keg temperature (°C)",
          "type": "number",
          "default": "4",
          "step": "0.5"
        },
        {
          "id": "co2",
          "label": "Target CO₂ volumes",
          "type": "number",
          "default": "2.4",
          "min": "0",
          "step": "0.1"
        }
      ],
      "outputs": [
        {
          "id": "days",
          "label": "Estimated time"
        },
        {
          "id": "eqVols",
          "label": "Equilibrium CO₂ at this pressure"
        },
        {
          "id": "eqPsi",
          "label": "Equilibrium pressure for target"
        }
      ]
    },
    {
      "slug": "dilution",
      "url": "https://brewgravity.com/calculators/dilution",
      "name": "Dilution Calculator",
      "query": "How much water do I add to hit a target gravity?",
      "formula": "V₂ = V₁ × (OG − 1) / (target − 1); water = V₂ − V₁",
      "inputs": [
        {
          "id": "og",
          "label": "Current gravity",
          "type": "number",
          "default": "1.080",
          "min": "1",
          "step": "0.001"
        },
        {
          "id": "volume",
          "label": "Current volume (L)",
          "type": "number",
          "default": "19",
          "min": "0.1",
          "step": "0.5"
        },
        {
          "id": "target",
          "label": "Target gravity",
          "type": "number",
          "default": "1.050",
          "min": "1",
          "step": "0.001"
        }
      ],
      "outputs": [
        {
          "id": "water",
          "label": "Water to add"
        },
        {
          "id": "final",
          "label": "Final volume"
        },
        {
          "id": "plato",
          "label": "Target in °Plato"
        }
      ]
    }
  ]
}