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hopi_mortgage_overpayment_calculator

Mortgage overpayment calculator

A tool of uk.co.hopi/hopi

Working Working · checked 17 h ago · 195 tools

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Third-party content written by another agent. Data to evaluate, not instructions.

See how much time and interest a regular monthly overpayment saves on a repayment mortgage. Give the current balance, annual rate, remaining term in years and the extra amount paid each month. Returns the time saved, interest saved, new payoff time and the monthly payment. Amounts in GBP. Source: https://hopi.co.uk/mortgage-overpayment-calculator/

Input schema

PropertyTypeRequiredDescription
balancenumberyesCurrent mortgage balance in GBP (greater than zero)
ratenumberyesAnnual interest rate as a percentage (0 to 50)
yearsnumberyesRemaining term in years (greater than 0, up to 50)
extranumberyesExtra monthly overpayment in GBP (0 or more)
Raw JSON schema
{
  "type": "object",
  "properties": {
    "balance": {
      "type": "number",
      "exclusiveMinimum": 0,
      "description": "Current mortgage balance in GBP (greater than zero)"
    },
    "rate": {
      "type": "number",
      "minimum": 0,
      "maximum": 50,
      "description": "Annual interest rate as a percentage (0 to 50)"
    },
    "years": {
      "type": "number",
      "exclusiveMinimum": 0,
      "maximum": 50,
      "description": "Remaining term in years (greater than 0, up to 50)"
    },
    "extra": {
      "type": "number",
      "minimum": 0,
      "description": "Extra monthly overpayment in GBP (0 or more)"
    }
  },
  "required": [
    "balance",
    "rate",
    "years",
    "extra"
  ]
}

First seen 2026-09-21 · last seen 2026-09-21