{
    "name": "UK Mortgage Calculator",
    "url": "https://calculators.geekmidst.com/calculators/mortgage-calculator-uk",
    "markdown": "https://calculators.geekmidst.com/calculators/mortgage-calculator-uk.md",
    "category": "Finance",
    "description": "Work out monthly UK mortgage payments on a repayment or interest-only basis from the price, deposit, rate and term, with LTV and a rate-rise stress test.",
    "summary": "Enter the property price, your deposit, the rate and the term. A repayment mortgage clears the loan by the end; an interest-only mortgage costs less each month but leaves the whole loan to repay at the end.",
    "also_called": [
        "Mortgage repayment calculator (UK)"
    ],
    "applies_to": "GB",
    "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": "price",
            "label": "Property price",
            "type": "number",
            "default": "300000"
        },
        {
            "name": "deposit",
            "label": "Deposit",
            "type": "number",
            "default": "30000"
        },
        {
            "name": "rate",
            "label": "Interest rate (per year)",
            "type": "number",
            "default": "4.5",
            "unit": "%"
        },
        {
            "name": "years",
            "label": "Mortgage term",
            "type": "number",
            "default": "25",
            "unit": "years"
        },
        {
            "name": "type",
            "label": "Mortgage type",
            "type": "segmented",
            "default": "repayment",
            "options": {
                "repayment": "Repayment",
                "interest_only": "Interest-only"
            }
        },
        {
            "name": "stress",
            "label": "Rate rise to test",
            "type": "number",
            "default": "3",
            "unit": "percentage points",
            "optional": true
        },
        {
            "name": "currency",
            "label": "Currency",
            "type": "currency",
            "default": "GBP"
        }
    ],
    "outputs": [
        {
            "key": "monthly",
            "label": "Monthly payment",
            "format": "currency"
        },
        {
            "key": "loan",
            "label": "Mortgage amount",
            "format": "currency"
        },
        {
            "key": "ltv",
            "label": "Loan-to-value (LTV)",
            "format": "percent"
        },
        {
            "key": "monthly_stressed",
            "label": "Monthly payment if the rate rises",
            "format": "currency"
        },
        {
            "key": "total_interest",
            "label": "Total interest over the term",
            "format": "currency"
        },
        {
            "key": "total_repaid",
            "label": "Total repaid",
            "format": "currency"
        }
    ],
    "formula": {
        "text": "Repayment: M = L × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1);  Interest-only: M = L × r;  LTV = L ÷ Price",
        "variables": {
            "L": "loan = price − deposit",
            "r": "annual rate ÷ 12 ÷ 100",
            "n": "term in months"
        }
    },
    "worked_example": {
        "inputs": {
            "price": "300000",
            "deposit": "30000",
            "rate": "4.5",
            "years": "25",
            "type": "repayment",
            "stress": "3",
            "currency": "GBP"
        },
        "steps": [
            "Loan = £300,000 − £30,000 = £270,000, an LTV of 90%.",
            "r = 4.5 ÷ 12 ÷ 100 = 0.00375 and n = 300; M = 270,000 × 0.00375 × 1.00375³⁰⁰ ÷ (1.00375³⁰⁰ − 1) = £1,500.75.",
            "At 7.5% (a 3-point rise) the same loan costs £1,995.28 a month."
        ],
        "result": "A £270,000 repayment mortgage at 4.5% over 25 years costs about £1,501 a month, rising to about £1,995 if rates went up by 3 points."
    },
    "interpretation": "Lower LTV bands generally get better rates, so a slightly bigger deposit can cut the cost twice. Most UK deals are fixed for 2–5 years and then revert to a variable rate, which the stress-test figure helps you plan for.",
    "assumptions": [
        "The rate stays the same for the whole term (in practice it changes when a fixed deal ends).",
        "Interest is charged monthly at the annual rate ÷ 12."
    ],
    "limitations": [
        "Stamp Duty Land Tax, arrangement fees, valuation and legal costs are not included.",
        "Lenders’ affordability checks are not modelled."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "What is LTV?",
            "answer": "Loan-to-value: the mortgage as a percentage of the property price. A £30,000 deposit on £300,000 means a 90% LTV."
        },
        {
            "question": "Repayment or interest-only?",
            "answer": "Repayment clears the debt by the end of the term. Interest-only is cheaper monthly, but you must repay the full loan at the end from another source, and lenders require a credible plan for that."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Mortgage Calculator",
            "url": "https://calculators.geekmidst.com/calculators/mortgage-calculator"
        },
        {
            "name": "Mortgage Amortization Calculator",
            "url": "https://calculators.geekmidst.com/calculators/mortgage-amortization-calculator"
        },
        {
            "name": "Down Payment Calculator",
            "url": "https://calculators.geekmidst.com/calculators/down-payment-calculator"
        }
    ],
    "disclaimer": "This calculator gives estimates for planning. It is not financial advice, and lenders’ actual terms, fees and rounding may differ.",
    "publisher": "GM¹X CalcVerse"
}