{
    "name": "Patient Appointment Lead Time Calculator",
    "url": "https://calculators.geekmidst.com/calculators/patient-appointment-lead-time-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/patient-appointment-lead-time-calculator.md",
    "category": "Healthcare operations",
    "description": "Paste request and appointment dates to get average, median and 90th-percentile appointment lead times and the share of patients seen within your target.",
    "summary": "Appointment lead time is the number of days from a patient’s request to the appointment. Paste one request date and appointment date per line to summarise access.",
    "also_called": [
        "Appointment wait time calculator",
        "Days to appointment calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "pairs",
            "label": "Request date, appointment date (one pair per line)",
            "type": "textarea",
            "default": "2026-03-02, 2026-03-16\n2026-03-02, 2026-03-05\n2026-03-10, 2026-04-09\n2026-03-20, 2026-03-27"
        },
        {
            "name": "target",
            "label": "Access target",
            "type": "number",
            "default": "14",
            "unit": "days"
        }
    ],
    "outputs": [
        {
            "key": "median",
            "label": "Median lead time",
            "format": "number"
        },
        {
            "key": "mean",
            "label": "Average lead time",
            "format": "number"
        },
        {
            "key": "p90",
            "label": "90th percentile",
            "format": "integer"
        },
        {
            "key": "longest",
            "label": "Longest",
            "format": "integer"
        },
        {
            "key": "within_pct",
            "label": "Seen within target",
            "format": "percent"
        },
        {
            "key": "count",
            "label": "Appointments",
            "format": "integer"
        }
    ],
    "formula": {
        "text": "Lead time = Appointment date − Request date (calendar days);  90th percentile = value at rank ⌈0.9 × n⌉ (nearest-rank);  Within target = count(lead time ≤ target) ÷ n",
        "variables": {
            "n": "number of appointments",
            "Target": "maximum acceptable days to appointment"
        }
    },
    "worked_example": {
        "inputs": {
            "pairs": "2026-03-02, 2026-03-16\n2026-03-02, 2026-03-05\n2026-03-10, 2026-04-09\n2026-03-20, 2026-03-27",
            "target": "14"
        },
        "steps": [
            "Lead times: 14, 3, 30 and 7 days; sorted 3, 7, 14, 30.",
            "Mean = 54 ÷ 4 = 13.5 days; median = (7 + 14) ÷ 2 = 10.5 days.",
            "90th percentile: rank ⌈3.6⌉ = 4, which is 30 days; 3 of 4 within 14 days = 75%."
        ],
        "result": "Half of these patients waited 10.5 days or less, but one in ten waited up to 30 days; 75% were seen within 14 days."
    },
    "interpretation": "The median shows the typical wait; the 90th percentile shows the long tail that patients complain about. A falling average with a rising 90th percentile means some patients are waiting longer.",
    "assumptions": [
        "Lead time is counted in calendar days, so a same-day appointment is 0 days.",
        "Every line is one completed or booked appointment."
    ],
    "limitations": [
        "Does not separate patients who chose a later date from those offered no earlier slot.",
        "Third-next-available appointment, another common access measure, needs the booking calendar rather than completed appointments."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Why is the median the headline figure?",
            "answer": "Waiting times are skewed by a few very long waits, which pull the average up. The median is the wait that half of patients beat."
        },
        {
            "question": "Should weekends count?",
            "answer": "This calculator counts calendar days, as patients experience them. Use the same convention every time you report."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Date Difference Calculator",
            "url": "https://calculators.geekmidst.com/calculators/date-difference-calculator"
        },
        {
            "name": "Average Calculator",
            "url": "https://calculators.geekmidst.com/calculators/average-calculator"
        },
        {
            "name": "Clinic Break-even Calculator",
            "url": "https://calculators.geekmidst.com/calculators/clinic-break-even-calculator"
        },
        {
            "name": "Patient Satisfaction Score Calculator",
            "url": "https://calculators.geekmidst.com/calculators/patient-satisfaction-score-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}