Loan interest

I=A−PI=A-P

What it does

Calculates loan interest from the supplied values.

When to use it

Use this finance formula when the named quantities are known.

Variables

Worked example
{
  "inputs": {
    "amount": 1250,
    "principal": 1000
  },
  "result": 250
}
Common mistakes
Check units, signs, brackets and that every value is entered in the stated units.