{
  "id": "blended-rate",
  "version": "dde52c1fcf75",
  "status": "published",
  "name": "Blended Rate Calculator",
  "question": "What is my blended rate?",
  "summary": "Works out the blended interest rate of several loans, the average of their rates weighted by balance, with the total yearly interest and the rate rounded up to 1/8% as for a federal consolidation loan.",
  "category": "finance",
  "subcategory": "loans",
  "url": "https://www.acalculator.org/finance/blended-rate-calculator",
  "markdown": "https://www.acalculator.org/finance/blended-rate-calculator.md",
  "kind": "function",
  "method": "blended rate = Σ(balance × rate) ÷ Σ balance; yearly interest = Σ(balance × rate ÷ 100); rounded = ⌈blended × 8⌉ ÷ 8.",
  "assumptions": [
    "Each balance is weighted by what you owe now; payments and different terms are not modelled.",
    "Interest in a year and a month is simple interest on today’s balances, before any payment.",
    "Typed amounts and rates are read exactly, so a shown rate rounds half up from its true value.",
    "The 1/8% rounding is the federal Direct Consolidation Loan rule; private lenders set their own rates."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "loans": {
        "title": "Loans",
        "description": "Each loan’s balance and its yearly interest rate, 2 to 20 loans.",
        "type": "array",
        "items": {
          "type": "object",
          "properties": {
            "b": {
              "title": "Balance",
              "description": "What you owe on this loan now.",
              "type": "number",
              "x-unit": "USD",
              "minimum": 0,
              "maximum": 1000000000000
            },
            "r": {
              "title": "Interest rate",
              "description": "This loan’s yearly interest rate.",
              "type": "number",
              "x-unit": "percent",
              "minimum": 0,
              "maximum": 100
            }
          }
        }
      }
    }
  },
  "outputs": {
    "blended": {
      "label": "Blended rate",
      "description": "Σ(balance × rate) ÷ Σ balance: the yearly rate that gives the same interest on the total.",
      "format": "percent"
    },
    "total": {
      "label": "Total balance",
      "description": "All the balances added up.",
      "format": "money"
    },
    "interest": {
      "label": "Interest in a year",
      "description": "Σ(balance × rate ÷ 100): one year of simple interest on today’s balances.",
      "format": "money"
    },
    "monthly": {
      "label": "Interest in a month",
      "description": "The yearly interest ÷ 12.",
      "format": "money"
    },
    "rounded": {
      "label": "Rounded up to 1/8%",
      "description": "The blended rate rounded up to the next 0.125%, as for a federal Direct Consolidation Loan.",
      "format": "percent"
    },
    "simple": {
      "label": "Plain average of the rates",
      "description": "The rates added up ÷ the number of loans, without weights, for comparison.",
      "format": "percent"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "loans": [
        {
          "balance": "200000",
          "rate": 3
        },
        {
          "balance": "50000",
          "rate": 7
        }
      ]
    },
    "outputs": {
      "blended": 3.8,
      "total": 250000,
      "interest": 9500,
      "monthly": 791.6666666666666,
      "rounded": 3.875,
      "simple": 5
    },
    "text": "Your blended rate is 3.8% on $250,000.00."
  },
  "examples": [
    {
      "given": {
        "loans": [
          {
            "balance": 200000,
            "rate": 3
          },
          {
            "balance": 50000,
            "rate": 7
          }
        ]
      },
      "expect": {
        "blended": 3.8,
        "total": 250000,
        "interest": 9500,
        "rounded": 3.875,
        "simple": 5
      },
      "source": "hand calculation in content.mdx: (200,000 × 3 + 50,000 × 7) ÷ 250,000 = 950,000 ÷ 250,000 = 3.8%; rounded up to 1/8%: Federal Student Aid, Student Loan Consolidation (the fixed rate is the weighted average of the interest rates on the loans being consolidated, rounded up to the nearest one-eighth of one percent), https://studentaid.gov/manage-loans/consolidation (retrieved 2026-10-02)"
    },
    {
      "given": {
        "loans": [
          {
            "balance": 5500,
            "rate": 5.5
          },
          {
            "balance": 7500,
            "rate": 6.53
          },
          {
            "balance": 3000,
            "rate": 4.99
          }
        ]
      },
      "expect": {
        "blended": 5.8871875,
        "rounded": 6,
        "interest": 941.95
      },
      "source": "hand calculation in content.mdx: (30,250 + 48,975 + 14,970) ÷ 16,000 = 94,195 ÷ 16,000 = 5.8871875%; Federal Student Aid, Student Loan Consolidation (the fixed rate is the weighted average of the interest rates on the loans being consolidated, rounded up to the nearest one-eighth of one percent), https://studentaid.gov/manage-loans/consolidation (retrieved 2026-10-02)"
    },
    {
      "given": {
        "loans": [
          {
            "balance": 10000,
            "rate": 4.5
          }
        ]
      },
      "expect": {
        "blended": 4.5,
        "rounded": 4.5,
        "monthly": 37.5
      },
      "source": "one loan: the blended rate is its own rate; a rate already on a 1/8% step stays; Federal Student Aid, Student Loan Consolidation (the fixed rate is the weighted average of the interest rates on the loans being consolidated, rounded up to the nearest one-eighth of one percent), https://studentaid.gov/manage-loans/consolidation (retrieved 2026-10-02)"
    }
  ],
  "sources": [
    "Federal Student Aid, Student Loan Consolidation (a Direct Consolidation Loan’s fixed rate is the weighted average of the interest rates on the loans being consolidated, rounded up to the nearest one-eighth of one percent). https://studentaid.gov/manage-loans/consolidation (retrieved 2026-10-02)"
  ],
  "related": [
    "debt-consolidation",
    "student-loan",
    "interest-rate",
    "loan"
  ],
  "changelog": []
}