{
    "name": "Contingency Budget Calculator",
    "url": "https://calculators.geekmidst.com/calculators/contingency-budget-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/contingency-budget-calculator.md",
    "category": "Construction",
    "description": "Add design and construction contingency percentages to a base cost to get the contingency sum, the total budget and contingency as a share of it.",
    "summary": "Contingency is money set aside for things that will happen but cannot yet be priced. Separate design and construction contingency so each can be drawn down on its own.",
    "also_called": [
        "Project contingency 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": "base_cost",
            "label": "Base cost estimate",
            "type": "number",
            "default": "800000"
        },
        {
            "name": "design_pct",
            "label": "Design contingency",
            "type": "number",
            "default": "5",
            "unit": "%"
        },
        {
            "name": "construction_pct",
            "label": "Construction contingency",
            "type": "number",
            "default": "10",
            "unit": "%"
        },
        {
            "name": "currency",
            "label": "Currency",
            "type": "currency",
            "default": "USD"
        }
    ],
    "outputs": [
        {
            "key": "total_budget",
            "label": "Total budget",
            "format": "currency"
        },
        {
            "key": "contingency_total",
            "label": "Total contingency",
            "format": "currency"
        },
        {
            "key": "design_amount",
            "label": "Design contingency",
            "format": "currency"
        },
        {
            "key": "construction_amount",
            "label": "Construction contingency",
            "format": "currency"
        },
        {
            "key": "share",
            "label": "Contingency share of budget",
            "format": "percent"
        }
    ],
    "formula": {
        "text": "Design = Base × d;  Construction = Base × c;  Budget = Base + Design + Construction",
        "variables": {
            "Base": "estimated cost without contingency",
            "d, c": "design and construction contingency percentages"
        }
    },
    "worked_example": {
        "inputs": {
            "base_cost": "800000",
            "design_pct": "5",
            "construction_pct": "10",
            "currency": "USD"
        },
        "steps": [
            "Design contingency = 800,000 × 5% = 40,000.",
            "Construction contingency = 800,000 × 10% = 80,000.",
            "Budget = 800,000 + 120,000 = 920,000; 120,000 ÷ 920,000 = 13.04%."
        ],
        "result": "An 800,000 base with 5% design and 10% construction contingency gives a 920,000 budget."
    },
    "interpretation": "Draw down design contingency as the design firms up and construction contingency as risks materialise. Unused contingency should be released, not absorbed into scope.",
    "assumptions": [
        "Both percentages apply to the base cost."
    ],
    "limitations": [
        "A flat percentage is a rule of thumb; a quantified risk register gives a better-founded figure for large projects."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "What percentage should I use?",
            "answer": "It depends on how complete the design is and how risky the work is. Ask your cost consultant or use your organisation’s guidance; the defaults here are examples only."
        },
        {
            "question": "Should escalation be part of contingency?",
            "answer": "Keep it separate. Use the Construction Cost Escalation Calculator for price changes over time."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Construction Cost Escalation Calculator",
            "url": "https://calculators.geekmidst.com/calculators/construction-cost-escalation-calculator"
        },
        {
            "name": "Construction Retention Calculator",
            "url": "https://calculators.geekmidst.com/calculators/construction-retention-calculator"
        },
        {
            "name": "Percentage Calculator",
            "url": "https://calculators.geekmidst.com/calculators/percentage-calculator"
        }
    ],
    "disclaimer": "Quantities are estimates. Confirm requirements with your engineer or supplier before ordering materials.",
    "publisher": "GM¹X CalcVerse"
}