{
  "slug": "big-purchase-real-cost",
  "title": "Big Purchase Real Cost Calculator",
  "heading": "Big Purchase Real Cost Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/big-purchase-real-cost",
  "summary": "The true lifetime cost of a large buy including financing, running costs and lost returns.",
  "description": "A sticker price is the smallest part of a large purchase. Financing adds interest, ownership adds recurring costs, and the cash spent stops earning. This calculator totals all four components across the years you expect to own the item — purchase, financing, running costs, and the opportunity cost of the money — then subtracts any resale value to produce a true cost and a cost per month of use. It is deliberately uncomfortable arithmetic, and it is the reason a purchase that feels affordable monthly can still be an expensive decision.",
  "formula": "True cost = price + financing interest + (running costs × years) + opportunity cost of cash deployed − resale value. Cost per month = true cost ÷ (years × 12).",
  "dateModified": "2026-08-25",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=big-purchase-real-cost",
  "inputs": [
    {
      "id": "price",
      "label": "Purchase price",
      "kind": "number",
      "hint": null,
      "default": 12000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "cashDown",
      "label": "Paid in cash up front",
      "kind": "number",
      "hint": null,
      "default": 4000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "apr",
      "label": "Financing APR on the remainder",
      "kind": "number",
      "hint": null,
      "default": 9.9,
      "unit": "%",
      "min": 0,
      "max": null
    },
    {
      "id": "termMonths",
      "label": "Financing term",
      "kind": "number",
      "hint": null,
      "default": 36,
      "unit": "months",
      "min": 1,
      "max": null
    },
    {
      "id": "running",
      "label": "Running costs",
      "kind": "number",
      "hint": "Insurance, maintenance, storage, fees",
      "default": 900,
      "unit": "$/yr",
      "min": 0,
      "max": null
    },
    {
      "id": "years",
      "label": "Years you'll own it",
      "kind": "number",
      "hint": null,
      "default": 6,
      "unit": "years",
      "min": 1,
      "max": null
    },
    {
      "id": "resale",
      "label": "Resale value at the end",
      "kind": "number",
      "hint": null,
      "default": 3000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "opportunity",
      "label": "Return the cash would have earned",
      "kind": "number",
      "hint": null,
      "default": 6,
      "unit": "%",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "trueCost",
      "label": "True lifetime cost",
      "format": "currency",
      "hint": null,
      "primary": true
    },
    {
      "id": "perMonth",
      "label": "Cost per month of ownership",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "financeInterest",
      "label": "Interest paid on financing",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "runningTotal",
      "label": "Running costs over the period",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "opportunityCost",
      "label": "Lost return on cash deployed",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "payment",
      "label": "Monthly finance payment",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "multiple",
      "label": "True cost as a multiple of price",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Purchase price: 12000 $",
      "Paid in cash up front: 4000 $",
      "Financing APR on the remainder: 9.9 %",
      "Financing term: 36 months",
      "Running costs: 900 $/yr",
      "Years you'll own it: 6 years",
      "Resale value at the end: 3000 $",
      "Return the cash would have earned: 6 %"
    ],
    "outputs": [
      "True lifetime cost: $17,353.51",
      "Cost per month of ownership: $241.02",
      "Interest paid on financing: $1,279.43",
      "Running costs over the period: $5,400.00",
      "Lost return on cash deployed: $1,674.08",
      "Monthly finance payment: $257.76",
      "True cost as a multiple of price: 1.45"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter purchase price ($).",
      "Enter paid in cash up front ($).",
      "Enter financing apr on the remainder (%).",
      "Enter financing term (months).",
      "Enter running costs ($/yr) — Insurance, maintenance, storage, fees.",
      "Enter years you'll own it (years).",
      "Enter resale value at the end ($).",
      "Enter return the cash would have earned (%).",
      "Read your true lifetime cost on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "price": 7200,
        "cashDown": 2400,
        "apr": 9.9,
        "termMonths": 24,
        "running": 550,
        "years": 4,
        "resale": 1800,
        "opportunity": 3.5999999999999996
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "price": 12000,
        "cashDown": 4000,
        "apr": 9.9,
        "termMonths": 36,
        "running": 900,
        "years": 6,
        "resale": 3000,
        "opportunity": 6
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "price": 19200,
        "cashDown": 6400,
        "apr": 9.9,
        "termMonths": 60,
        "running": 1450,
        "years": 10,
        "resale": 4800,
        "opportunity": 9.600000000000001
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "Is opportunity cost a real cost?",
      "a": "It is real in the sense that the money had an alternative use — but only if you would genuinely have invested it. If the cash would have sat in checking, set the return input to your savings rate instead so the figure stays honest."
    },
    {
      "q": "Why does 0% financing still show a cost?",
      "a": "Because financing interest is only one of four components. Even at 0% you carry running costs, depreciation captured through the resale figure, and, if you also paid cash up front, the return that cash is no longer earning."
    },
    {
      "q": "How should I estimate resale value?",
      "a": "Look up actual completed sales for the same item at the age you plan to sell, not asking prices. For most consumer goods the honest answer is close to zero after a few years; vehicles, tools, and some instruments are the notable exceptions."
    },
    {
      "q": "How do I use the cost per month?",
      "a": "Compare it against renting, subscribing, or simply not owning. If a boat costs several hundred dollars per month of ownership and you use it six weekends a year, the per-use cost makes the alternative obvious in a way the sticker price never does."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/buy-vs-lease-car",
    "https://www.revenuelab.fyi/toolbox/subscription-audit-annual",
    "https://www.revenuelab.fyi/toolbox/sinking-fund-monthly"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Big Purchase Real Cost Calculator (https://www.revenuelab.fyi/toolbox/big-purchase-real-cost)"
}