keisoku

Interest Rate Converter (Annual, Monthly, Per-Diem)

Enter an annual rate to instantly convert it to monthly, daily, per-diem (interest on ¥100 per day), and effective annual rates. Great for comparing loans, card loans, and savings.

Input

%
Compounding frequency (used for effective annual rate)

Result

Converting an annual rate of 15%

1.25% (monthly)

Annual

15 %

Monthly

1.25 %

Daily

0.041096 %

Per-diem (¥100 / day)

4.109589 sen

Effective annual (Monthly (12×/year) compounding)

16.075452 %

Monthly = annual ÷ 12, daily = annual ÷ 365, and the per-diem rate (hibu) = annual ÷ 365 × 100, expressed in sen as the one-day interest on ¥100 of principal. The effective annual rate converts the nominal rate at the chosen compounding frequency into an equivalent yearly compounded rate, calculated as (1 + annual ÷ 12)^12 − 1.

How it works

  • The monthly rate is the annual rate divided by 12 (monthly = annual ÷ 12), a simple pro-rata conversion.
  • The daily rate is the annual rate divided by 365 (daily = annual ÷ 365), treating one year as 365 days.
  • The per-diem rate (hibu) is the interest in sen on ¥100 of principal held or borrowed for one day, calculated as annual ÷ 365 × 100 (¥1 = 100 sen).
  • The effective annual rate (EAR) is the nominal rate run at the chosen compounding frequency, converted to a yearly compounded rate via (1 + annual ÷ m)^m − 1, where m is the number of compounding periods per year. Higher compounding frequency makes the EAR exceed the nominal rate.
  • The compounding frequency can be set to yearly, semiannual (2×), quarterly (4×), monthly (12×), or daily (365×) for comparing effective annual rates.
  • Results are approximate. Actual interest depends on each institution's day-count conventions, rounding, and contract terms. Confirm exact amounts with your contract or financial institution.