Simple Interest Calculator

Calculate simple interest from principal, annual rate, and time in years, quarters, months, or days. See the interest and final amount.

Formula

Interest = principal × (annual rate ÷ 100) × time in years.

For months, quarters, or days, time is converted into years first. Days use a 365-day year.

Calculation with your values

{
  "calculator": "simple-interest-calculator",
  "input_types": [
    "float",
    "float",
    "float",
    "dropdown"
  ],
  "input_labels": [
    "P",
    "R",
    "T",
    "n"
  ],
  "input_values": [
    "10000.00",
    "4.0",
    "5",
    "1"
  ],
  "input_units": [
    "currency",
    "percentage",
    "",
    ""
  ],
  "extra": {
    "n": {
      "items": [
        [
          "Years",
          1
        ],
        [
          "Quarters",
          4
        ],
        [
          "Months",
          12
        ],
        [
          "Days",
          365
        ]
      ]
    }
  },
  "intermediates": [
    [
      "r",
      " R /100"
    ],
    [
      "t",
      " T / n "
    ]
  ],
  "input_descriptions": [
    "Principal Amount",
    "Annual Interest Rate",
    "Time",
    "Factor adjusted for Time in years when Months/Quarters/Days are selected<br>n = 1, for Years<br>n = 4, for Quarters<br>n = 12, for Months<br>n = 365, for Days"
  ],
  "title": "Simple Interest",
  "category": "Financial",
  "formula_mathjax": "\\({\\ P  r  t }\\)",
  "formula_mathjax_sub": "\\({\\  P * r * t }\\)",
  "formula": " P * r * t ",
  "op_label": "Interest",
  "explanation": "Calculate simple interest from principal, annual rate, and time in years, quarters, months, or days. See the interest and final amount.",
  "template": "calculator"
}