{
    "name": "Shoe Size Converter",
    "url": "https://calculators.geekmidst.com/calculators/shoe-size-converter",
    "markdown": "https://calculators.geekmidst.com/calculators/shoe-size-converter.md",
    "category": "Everyday tools",
    "description": "Convert adult shoe sizes between UK, US men’s, US women’s and EU, or find your size from foot length in cm or inches, using the standard sizing formulas.",
    "summary": "Shoe sizing systems are all based on length, just with different units and starting points. Enter your foot length, or a size you know, to see the matching size in each system.",
    "also_called": [
        "Shoe size chart",
        "Shoe size conversion 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": "mode",
            "label": "Start from",
            "type": "segmented",
            "default": "foot",
            "options": {
                "foot": "Foot length",
                "size": "A shoe size"
            }
        },
        {
            "name": "foot",
            "label": "Foot length (heel to longest toe)",
            "type": "number",
            "default": "27",
            "shown_when": {
                "mode": "foot"
            }
        },
        {
            "name": "foot_unit",
            "label": "Measured in",
            "type": "segmented",
            "default": "cm",
            "options": {
                "cm": "cm",
                "in": "inches"
            },
            "shown_when": {
                "mode": "foot"
            }
        },
        {
            "name": "system",
            "label": "Sizing system",
            "type": "select",
            "default": "uk",
            "options": {
                "uk": "UK",
                "us_men": "US men’s",
                "us_women": "US women’s",
                "eu": "EU (Paris points)",
                "mondo": "Mondopoint (mm)"
            },
            "shown_when": {
                "mode": "size"
            }
        },
        {
            "name": "size",
            "label": "Size",
            "type": "number",
            "default": "8",
            "shown_when": {
                "mode": "size"
            }
        }
    ],
    "outputs": [
        {
            "key": "uk",
            "label": "UK",
            "format": "number"
        },
        {
            "key": "us_men",
            "label": "US men’s",
            "format": "number"
        },
        {
            "key": "us_women",
            "label": "US women’s",
            "format": "number"
        },
        {
            "key": "eu",
            "label": "EU",
            "format": "number"
        },
        {
            "key": "mondopoint",
            "label": "Mondopoint (foot length)",
            "format": "integer"
        },
        {
            "key": "foot_cm",
            "label": "Foot length",
            "format": "number"
        },
        {
            "key": "foot_in",
            "label": "Foot length",
            "format": "number"
        }
    ],
    "formula": {
        "text": "UK ≈ 3 × foot (in) − 23;  US men ≈ 3 × foot (in) − 22;  US women ≈ 3 × foot (in) − 21;  EU ≈ 1.5 × foot (cm) + 2;  Mondopoint = foot length in mm",
        "variables": {
            "foot": "heel-to-toe foot length; the shoe’s last is about 1.5 cm longer, which the constants already allow for"
        }
    },
    "worked_example": {
        "inputs": {
            "mode": "foot",
            "foot": "27",
            "foot_unit": "cm",
            "system": "uk",
            "size": "8"
        },
        "steps": [
            "27 cm ÷ 2.54 = 10.63 in.",
            "UK = 3 × 10.63 − 23 = 8.89, rounded to the nearest half size: 9. US men’s adds 1 (10); US women’s adds 2 (11).",
            "EU = 1.5 × 27 + 2 = 42.5. Mondopoint is the foot length in millimetres: 270."
        ],
        "result": "A 27 cm foot is about UK 9, US men’s 10, US women’s 11 and EU 42.5."
    },
    "interpretation": "Treat the result as a starting point. Brands size their lasts differently, so the same foot can be an EU 42 in one brand and a 43 in another; check the brand’s own chart when it gives one.",
    "assumptions": [
        "Adult sizes. Sizes are rounded to the nearest half size.",
        "US women’s uses the scale two sizes above UK; some brands use US men’s + 1.5 instead."
    ],
    "limitations": [
        "Width is not considered.",
        "Children’s sizes use different scales and are not covered.",
        "Brand and style (boots, running shoes, high heels) change the fit."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "How do I measure my foot?",
            "answer": "Stand on a sheet of paper with your heel against a wall, mark the tip of your longest toe and measure from the wall. Measure both feet in the evening and use the longer one."
        },
        {
            "question": "Why is a UK size smaller than the US size?",
            "answer": "Both count in barleycorns (⅓ inch), but the scales start from different points: US men’s is one size above UK, and US women’s is usually two above."
        }
    ],
    "sources": [
        {
            "title": "Wikipedia — Shoe size (sizing system formulas)",
            "url": "https://en.wikipedia.org/wiki/Shoe_size"
        }
    ],
    "related": [
        {
            "name": "Length Converter",
            "url": "https://calculators.geekmidst.com/calculators/length-converter"
        },
        {
            "name": "Tyre Size Calculator",
            "url": "https://calculators.geekmidst.com/calculators/tire-size-calculator"
        },
        {
            "name": "Ratio Calculator",
            "url": "https://calculators.geekmidst.com/calculators/ratio-calculator"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}