{
    "name": "Email Click-to-Open Rate Calculator",
    "url": "https://calculators.geekmidst.com/calculators/email-click-to-open-rate-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/email-click-to-open-rate-calculator.md",
    "category": "Marketing analytics",
    "description": "Calculate click-to-open rate (unique clicks ÷ unique opens), open rate and click rate (both ÷ delivered) for an email campaign.",
    "summary": "Click-to-open rate shows how many people who opened an email went on to click: unique clicks divided by unique opens.",
    "also_called": [
        "CTOR calculator",
        "Email open rate 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": "delivered",
            "label": "Emails delivered",
            "type": "number",
            "default": "10000"
        },
        {
            "name": "unique_opens",
            "label": "Unique opens",
            "type": "number",
            "default": "2500"
        },
        {
            "name": "unique_clicks",
            "label": "Unique clicks",
            "type": "number",
            "default": "300"
        }
    ],
    "outputs": [
        {
            "key": "ctor",
            "label": "Click-to-open rate",
            "format": "percent"
        },
        {
            "key": "open_rate",
            "label": "Open rate (of delivered)",
            "format": "percent"
        },
        {
            "key": "click_rate",
            "label": "Click rate (of delivered)",
            "format": "percent"
        }
    ],
    "formula": {
        "text": "CTOR = Unique clicks ÷ Unique opens × 100;  Open rate = Unique opens ÷ Delivered × 100;  Click rate = Unique clicks ÷ Delivered × 100",
        "variables": {
            "Unique opens": "recipients who opened (CTOR denominator)",
            "Delivered": "emails that did not bounce (open- and click-rate denominator)"
        }
    },
    "worked_example": {
        "inputs": {
            "delivered": "10000",
            "unique_opens": "2500",
            "unique_clicks": "300"
        },
        "steps": [
            "CTOR = 300 ÷ 2,500 × 100 = 12%.",
            "Open rate = 2,500 ÷ 10,000 × 100 = 25%.",
            "Click rate = 300 ÷ 10,000 × 100 = 3%."
        ],
        "result": "300 clickers among 2,500 openers is a 12% click-to-open rate; 3% of all delivered recipients clicked."
    },
    "interpretation": "Open rate reflects the subject line and sender; CTOR reflects the content once opened. A high open rate with a low CTOR suggests the email did not deliver on its subject line.",
    "assumptions": [
        "Opens and clicks are unique (each recipient counted once)."
    ],
    "limitations": [
        "Privacy features such as Apple Mail Privacy Protection record opens automatically, inflating opens and lowering CTOR. Click-based metrics are more reliable."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "Why can someone click without an open being recorded?",
            "answer": "If images are blocked the open pixel never loads. Most email platforms count a click as an open, which is why clicks cannot exceed opens here."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Email Bounce Rate Calculator",
            "url": "https://calculators.geekmidst.com/calculators/email-bounce-rate-calculator"
        },
        {
            "name": "Email Unsubscribe Rate Calculator",
            "url": "https://calculators.geekmidst.com/calculators/email-unsubscribe-rate-calculator"
        },
        {
            "name": "Click-Through Rate Calculator",
            "url": "https://calculators.geekmidst.com/calculators/click-through-rate-calculator"
        },
        {
            "name": "Email Subscriber Growth Calculator",
            "url": "https://calculators.geekmidst.com/calculators/email-subscriber-growth-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}