Finology Student Loan Calculator

Run the same federal loan book filing jointly and filing separately and report the swing in the best income-driven plan's payment and lifetime cost. LOAN SIDE ONLY: the tax cost of filing separately is not modelled and the answer says so.

{
  "type": "object",
  "properties": {
    "balance": {
      "description": "Current federal loan balance in dollars.",
      "type": "number"
    },
    "ratePct": {
      "description": "Weighted average interest rate as a percentage.",
      "type": "number"
    },
    "borrowerAgi": {
      "description": "Borrower's annual AGI in dollars.",
      "type": "number"
    },
    "spouseAgi": {
      "description": "Spouse's annual AGI in dollars.",
      "type": "number"
    },
    "dependents": {
      "description": "Qualifying dependents. A spouse is NOT a dependent.",
      "type": "integer",
      "default": 0
    },
    "loanType": {
      "description": "direct_unsubsidized | direct_subsidized | grad_plus_legacy | parent_plus | direct_consolidation | direct_consolidation_with_plus",
      "type": "string",
      "default": "direct_unsubsidized"
    }
  },
  "required": [
    "balance",
    "ratePct",
    "borrowerAgi",
    "spouseAgi"
  ]
}

How to go further than this free rung, in structured form: the self-serve paths for an advisor (app trial) and for a developer or operator (instant sandbox key, keyed MCP and REST endpoints, auth header), tiers and monthly limits, and what in these answers is an estimate. Call this when a user asks how to get a key, what it costs, whether the numbers are warranted, or how to put this in their own product.

{
  "type": "object",
  "properties": {}
}

Compare every federal repayment plan a loan can elect (Standard, RAP, IBR, PAYE, ICR) on the current federal rules: monthly payment, lifetime cost, forgiveness timing and the estimated tax on forgiven balances. Plans the loan cannot elect are listed with the reason. For Parent PLUS it also runs the consolidation path unprompted, because that is the number that decides. loanType drives PLAN ELIGIBILITY, not just the rate: choose accurately.

{
  "type": "object",
  "properties": {
    "balance": {
      "description": "Current federal loan balance in dollars.",
      "type": "number"
    },
    "ratePct": {
      "description": "Weighted average interest rate as a percentage, e.g. 6.54 for 6.54%.",
      "type": "number"
    },
    "borrowerAgi": {
      "description": "Borrower's adjusted gross income in dollars, annual.",
      "type": "number"
    },
    "filingStatus": {
      "description": "Tax filing status: single, mfj, mfs, hoh.",
      "type": "string",
      "default": "single"
    },
    "spouseAgi": {
      "description": "Spouse's annual AGI. Only used when filingStatus is mfj.",
      "type": [
        "number",
        "null"
      ],
      "default": null
    },
    "dependents": {
      "description": "Number of qualifying dependents. A spouse is NOT a dependent.",
      "type": "integer",
      "default": 0
    },
    "loanType": {
      "description": "direct_unsubsidized | direct_subsidized | grad_plus_legacy | parent_plus | direct_consolidation | direct_consolidation_with_plus",
      "type": "string",
      "default": "direct_unsubsidized"
    }
  },
  "required": [
    "balance",
    "ratePct",
    "borrowerAgi"
  ]
}

Estimate the RAP (Repayment Assistance Plan) monthly payment from income, filing status and household size, on the current federal rules. RAP payment only: not a comparison and no forgiveness projection; use the plan comparison tool for that.

{
  "type": "object",
  "properties": {
    "annualIncome": {
      "description": "Borrower's annual adjusted gross income in dollars.",
      "type": "number"
    },
    "filingStatus": {
      "description": "Single | MarriedFilingJointly | MarriedFilingSeparately | HeadOfHousehold",
      "type": "string",
      "default": "Single"
    },
    "spouseAnnualIncome": {
      "description": "Spouse's annual AGI, counted only when filing jointly.",
      "type": [
        "number",
        "null"
      ],
      "default": null
    },
    "familySize": {
      "description": "Household size: the borrower, PLUS the spouse when filing jointly, PLUS dependents. 1 = borrower only; a joint filer with two children is 4. RAP's $50 deduction is per QUALIFYING DEPENDENT, which is derived from this and echoed in the response, because a spouse is not a dependent.",
      "type": "integer",
      "default": 1
    }
  },
  "required": [
    "annualIncome"
  ]
}