{
  "id": "drip-rate",
  "version": "1cce0eecdff4",
  "status": "published",
  "name": "Drip Rate Calculator",
  "question": "What is the IV drip rate?",
  "summary": "Works out an IV drip rate in drops per minute from the volume, the infusion time, and the drop factor of the giving set, with the same infusion as a pump rate in mL per hour.",
  "category": "health",
  "subcategory": "clinical",
  "url": "https://www.acalculator.org/health/drip-rate-calculator",
  "markdown": "https://www.acalculator.org/health/drip-rate-calculator.md",
  "kind": "function",
  "method": "Drops per minute = volume (mL) × drop factor (gtt/mL) ÷ time (minutes). mL per hour = volume (mL) ÷ time (hours).",
  "assumptions": [
    "A gravity infusion at a steady rate; the drop factor is the one printed on the giving set.",
    "The page works out the rate for an order a clinician has written. It does not choose a fluid, a volume, or a time.",
    "The rate is worked from the exact typed values and rounded once: 2 decimals, and to a whole drop with halves up."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "volume": {
        "title": "Volume to infuse",
        "description": "The volume of fluid to give, from 1 mL to 10 L.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "volume",
        "minimum": 0.000001,
        "maximum": 0.01
      },
      "time": {
        "title": "Infusion time",
        "description": "How long the infusion runs, from 1 minute to 72 hours.",
        "type": [
          "number",
          "string"
        ],
        "x-quantity": "time",
        "minimum": 60,
        "maximum": 259200
      },
      "df": {
        "title": "Drop factor (gtt/mL)",
        "description": "Drops per mL of the giving set, printed on its package: often 10, 15, or 20 (macrodrip) or 60 (microdrip).",
        "type": "integer",
        "minimum": 1,
        "maximum": 100
      }
    }
  },
  "outputs": {
    "rate": {
      "label": "Drip rate (gtt/min)",
      "description": "Volume in mL × drop factor ÷ time in minutes, to 2 decimals.",
      "format": "number"
    },
    "drops": {
      "label": "Drops per minute, whole",
      "description": "The drip rate rounded to the nearest whole drop (halves up), which is what can be counted.",
      "format": "integer"
    },
    "mlPerHour": {
      "label": "Pump rate (mL/h)",
      "description": "Volume in mL ÷ time in hours, to 2 decimals.",
      "format": "number"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "volume": "1000 mL",
      "time": "8 h",
      "df": 20
    },
    "outputs": {
      "rate": 41.666666666666664,
      "drops": 42,
      "mlPerHour": 125
    },
    "text": "1,000 mL over 8 h with a 20 gtt/mL set runs at 41.67 drops a minute (125 mL/h)."
  },
  "examples": [
    {
      "given": {
        "volume": 0.001,
        "time": 28800,
        "df": 20
      },
      "expect": {
        "rate": 41.666666666666664,
        "drops": 42,
        "mlPerHour": 125
      },
      "source": "Open RN Nursing Skills (Ernstmeyer et al.), 5.14: gtt/min = mL × gtt/mL ÷ min: 1000 × 20 ÷ 480 = 41.67; 1000 ÷ 8 = 125 mL/h (hand calculation in content.mdx)"
    },
    {
      "given": {
        "volume": 0.0001,
        "time": 1800,
        "df": 15
      },
      "expect": {
        "rate": 50,
        "drops": 50,
        "mlPerHour": 200
      },
      "source": "100 × 15 ÷ 30 = 50 gtt/min; 100 ÷ 0.5 = 200 mL/h (hand calculation in content.mdx)"
    },
    {
      "given": {
        "volume": 0.00025,
        "time": 7200,
        "df": 60
      },
      "expect": {
        "rate": 125,
        "drops": 125,
        "mlPerHour": 125
      },
      "source": "250 × 60 ÷ 120 = 125 gtt/min = 125 mL/h (hand calculation in content.mdx)"
    },
    {
      "given": {
        "volume": 0.0005,
        "time": 14400,
        "df": 10
      },
      "expect": {
        "rate": 20.833333333333332,
        "drops": 21,
        "mlPerHour": 125
      },
      "source": "500 × 10 ÷ 240 = 20.83 gtt/min, 21 whole drops (hand calculation in content.mdx)"
    },
    {
      "given": {
        "volume": 0.00005,
        "time": 2400,
        "df": 15
      },
      "expect": {
        "rate": 18.75,
        "drops": 19,
        "mlPerHour": 75
      },
      "source": "50 × 15 ÷ 40 = 18.75 gtt/min, 19 whole drops (halves up); 50 ÷ (40/60) = 75 mL/h (hand calculation)"
    }
  ],
  "sources": [
    "Ernstmeyer K, Christman E, eds. Nursing Skills (Open RN). 5.14 IV Infusion by Gravity (drop factors and drops per minute). https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/05%3A_Math_Calculations/5.14%3A_IV_Infusion_by_Gravity (retrieved 2026-10-05)"
  ],
  "related": [],
  "changelog": [
    {
      "date": "2026-10-05",
      "note": "Published after this site's editorial review against the cited sources (no clinician review); the page notices say so."
    }
  ]
}