Simple interest (rate)

Reverse solve rate from principal, future value, and elapsed days.

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Calculation specification

Reviewed on:

Formula basis

Basis rate=(FV/PV−1)×d/days×100, where d is 365, 360, 30, or 1.

Calculation method

Derives the rate on the selected basis from principal, future value, and elapsed days.

Exclusions and checks required

  • Principal and days must be positive, with no interim cash flows.
  • The output is on the selected basis and cannot be compared directly with a rate using another basis.

Example input:：Rate for JPY 1 million to become JPY 1.1 million in 365 days

simpleMode
365
principal
1000000
futureValue
1100000
days
365
digits
10

This reverse rate excludes tax and costs.

FAQ

Who is this calculator for? Simple interest (rate)

Reverse solve rate from principal, future value, and elapsed days.

What values should I enter?

Applies to: Simple interest / r = (FV/PV − 1) × basis ÷ days

How should I interpret this estimate?

Derives the rate on the selected basis from principal, future value, and elapsed days.

How to use

  1. Enter your input values and press Calculate.
  2. Review the result and compare it with expected context.
  3. Basis rate=(FV/PV−1)×d/days×100, where d is 365, 360, 30, or 1.