Simple interest (principal)

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

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Calculation specification

Reviewed on:

Formula basis

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

Calculation method

Derives principal from a simple-interest future value, rate, elapsed days, and selected day basis.

Exclusions and checks required

  • The model assumes a constant simple rate and fixed day basis.
  • Tax, fees, actual start and maturity dates, and interim cash flows are excluded.

Example input:：Principal behind JPY 1.1 million after 365 days at 5%

simpleMode
365
simpleRate
5
futureValue
1100000
days
365

This algebraic reversal is not a market present-value assessment.

FAQ

Who is this calculator for? Simple interest (principal)

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

What values should I enter?

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

How should I interpret this estimate?

Derives principal from a simple-interest future value, rate, elapsed days, and selected day basis.

How to use

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