Simple interest (future value)

Compute future value and interest with 365-day, 360-day, monthly, or day-count basis.

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Calculation specification

Reviewed on:

Formula basis

For basis d, interest I=PV×(rate/100)×days/d and FV=PV+I. The basis is 365, 360, 30, or 1 respectively.

Calculation method

Calculates simple interest and future value from principal, rate, elapsed days, and a 365-day, 360-day, monthly, or daily basis.

Exclusions and checks required

  • Interest does not compound, and actual calendar conventions or business-day adjustments are not modeled.
  • Tax, fees, principal changes, and yen rounding are excluded.

Example input:：JPY 1 million at 5% simple annual interest for 365 days

simpleMode
365
simpleRate
5
principal
1000000
days
365

The value follows the selected mathematical day basis.

FAQ

Who is this calculator for? Simple interest (future value)

Compute future value and interest with 365-day, 360-day, monthly, or day-count basis.

What values should I enter?

Applies to: Simple interest / I = PV × r × days ÷ basis, FV = PV + I

How should I interpret this estimate?

Calculates simple interest and future value from principal, rate, elapsed days, and a 365-day, 360-day, monthly, or daily basis.

How to use

  1. Enter your input values and press Calculate.
  2. Review the result and compare it with expected context.
  3. For basis d, interest I=PV×(rate/100)×days/d and FV=PV+I. The basis is 365, 360, 30, or 1 respectively.