Compound Interest Calculator Tokyo

Compound Interest Calculator for Tokyo

Savings accounts and deposits in Tokyo are priced off the Bank of Japan policy rate, which stood at 1.25% at the end of September 2026. National consumer price inflation was 2.10% in September 2026, so a saver earning exactly the policy rate would have a real return of -0.83% a year before tax.

Facts that change the answer

• Bank of Japan policy rate: 1.25% (September 2026, BIS series)
• Annual CPI inflation: 2.10% (September 2026)
• Real return at the policy rate: -0.83% per year (computed as (1 + 1.25%) / (1 + 2.10%) minus 1)
• Policy rate at each December: 2016 -0.1%, 2017 -0.1%, 2018 -0.1%, 2019 -0.1%, 2020 -0.1%, 2021 -0.1%, 2022 -0.1%, 2023 -0.1%, 2024 0.25%, 2025 0.75%
• Policy rate moves since January 2020 (month-end data): March 2024 -0.1% to 0.05%; August 2024 0.05% to 0.25%; January 2025 0.25% to 0.5%; December 2025 0.5% to 0.75%; June 2026 0.75% to 1%; September 2026 1% to 1.25%
• In 2 of the last 10 years the December policy rate was above that year's average inflation

Worked example for Tokyo

Start with JPY 1,500,000, add JPY 15,000 a month and use 1.25% compounded monthly. After 10 years you would have JPY 3,615,888 from JPY 3,300,000 of deposits; after 20 years JPY 6,013,348 from JPY 5,100,000. These amounts in Japanese yen are only examples; real deposit rates offered by banks in Tokyo are usually below or above the policy rate depending on the term and the bank.

To see what that balance is worth in today's money, take inflation into account: at 2.10% a year, JPY 3,615,888 in ten years has the buying power of about JPY 2,937,966 now. Recent history for Tokyo's currency: 2020: -0.1% rate vs 0.0% inflation, 2021: -0.1% rate vs -0.2% inflation, 2022: -0.1% rate vs 2.5% inflation, 2023: -0.1% rate vs 3.3% inflation, 2024: 0.25% rate vs 2.7% inflation, 2025: 0.75% rate vs 3.2% inflation.

If you hold the money in a fixed deposit, the rate you lock in matters more than the compounding frequency. On JPY 1,500,000 over 10 years at 1.25%, switching from yearly to monthly compounding adds only JPY 1,206, while a rate 1 point higher adds JPY 178,476.

Sources: BIS central bank policy rates · BIS consumer price statistics. Checked 5 November 2026. For how the maths works, see the Compound Interest Calculator guide.