Monthly Investment Calculator — Japan
See how a monthly investment grows over time at Japan's historical returns. No signup, no account needed.
Enter a monthly amount, a return rate between 0% and 100%, and a duration above zero (up to 50 years) to see results.
Where to invest in Japan
Nikkei 225 long-term ≈ 5–7% nominal, global ETFs ≈ 7–10% in JPY terms. New NISA annual limit ¥3.6M (¥1.8M accumulation). Platforms: SBI Securities, Rakuten Securities, Monex.
Returns are long-term historical averages, not guarantees - markets fall as well as rise. Invest for the long term and diversify.
The power of compounding
Investing ￥75,000 per month for 15 years at 5% p.a.:
- Future value: ￥20,130,199
- Total invested: ￥13,500,000
- Estimated gains: ￥6,630,199
That is roughly 1.5× your money - most of it from compounding. Scale the ￥75,000 to your own monthly amount, and remember that starting earlier matters more than investing more.
How to start - and stay - invested in Japan
- Automate a fixed monthly amount so you invest through good months and bad.
- Start small; you can raise the amount as your income grows.
- Favour low-cost, diversified funds over picking individual stocks.
- Stay invested through market dips - time in the market beats timing the market.
The new NISA tax break — and what return to assume
Japan’s version of a SIP is a monthly tsumitate (積立) plan — a fixed amount invested every month. Since 2024 the new NISA Tsumitate growth allowance lets residents invest up to a generous annual cap and pay zero tax on the gains and dividends; outside that allowance, investment income is taxed at a flat 20.315%. This is the single most important number on this page.
Don’t treat an "expected return" as a promise. Long-run global and Japanese equity funds are commonly modelled at 3–7% p.a.; this calculator defaults to 5%, labelled an assumption, not a guarantee. For context, the Bank of Japan raised its policy rate to 1.0% on 16 June 2026 and to 1.25% on 18 September 2026, so cash savings finally earn a positive return too — though most tsumitate investors still use equity funds for long-horizon growth.
Worked example: a realistic tsumitate plan
Investing ¥30,000 per month for 20 years at an assumed 5% annual return (monthly compounding):
- Future value: ≈ ¥12.33 million
- Total contributed: ¥7.2 million
- Estimated growth: ≈ ¥5.13 million
Inside the new NISA tsumitate allowance, that ¥5.13 million of growth is tax-free; outside it, it would be taxed at 20.315%. Use the calculator above with your own monthly amount to see your projection.
Frequently Asked Questions
How does a monthly investment work in Japan?
You invest a fixed amount each month into funds or an index. You buy more units when prices are low and fewer when high (cost averaging), and returns compound over time.
What return can I expect in Japan?
Long-term historical equity returns are around 5% per year here, though any single year can be sharply up or down. Nikkei 225 long-term ≈ 5–7% nominal, global ETFs ≈ 7–10% in JPY terms. New NISA annual limit ¥3.6M (¥1.8M accumulation). Platforms: SBI Securities, Rakuten Securities, Monex.
How much do I need to start investing in Japan?
Most platforms let you start small and increase later. Setting up an automatic monthly investment builds discipline and smooths out market timing.
Should I invest a lump sum or monthly in Japan?
Investing monthly spreads your entry across market ups and downs (cost averaging) and is easier to budget. A lump sum can do better in a steadily rising market but carries more timing risk.
Is investing better than a fixed deposit in Japan?
Investing targets higher long-term growth but carries market risk; fixed deposits are safer but usually return less. Many people hold both, matched to their time horizon.
What is the new NISA and how does it change the maths?
Gains and dividends inside the new NISA's tsumitate growth allowance are tax-free; outside it, investment income is taxed at a flat 20.315%. That difference compounds significantly over 20+ years.
Tsumitate NISA vs Growth NISA — what's the difference?
The new NISA has two allowances that can be used together: a Tsumitate (accumulation) frame for regular fund investing and a Growth frame with a higher annual limit and more flexibility. Most monthly-SIP investors focus on the Tsumitate side.
Is my SIP return guaranteed in Japan?
No — this calculator models an assumption (5% is the default), not a promise. Equity funds can rise or fall with the market; only the compounding maths is guaranteed, not the return itself.
Does the Bank of Japan's 2026 rate hike affect my SIP?
The BOJ's moves to 1.0% (16 June 2026) and 1.25% (18 September 2026) mainly lifts returns on cash and bonds, not equities directly. It's a reason cash savings are no longer earning near-zero, but it doesn't change the case for a diversified equity tsumitate plan.
iDeCo vs NISA for regular investing — which first?
iDeCo is a pension-linked wrapper with its own contribution limits and lock-in until retirement age; NISA is more flexible with no withdrawal restriction. Many residents use NISA for general goals and iDeCo alongside it for retirement-specific tax relief.
What platforms do Japanese investors use for tsumitate plans?
SBI Securities, Rakuten Securities and Monex are among the most widely used online brokers for monthly tsumitate investing, each offering a range of low-cost index funds inside the NISA framework.
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Sources
Return assumptions and rates are compiled from each country's central-bank publications, recognized market-index data and the typical offerings of major providers, reviewed for 2026 and subject to change. Returns are long-term historical averages, not guarantees. See our methodology and editorial policy for how we source and update this data.
Additional sources for this page
Bank of Japan, Change in the Guideline for Market Operations (16 June 2026; accessed 15 October 2026). Bank of Japan, Statement on Monetary Policy (18 September 2026; call rate around 1.25%; accessed 15 October 2026). New NISA framework and the 20.315% flat rate on investment income outside it: Japan's NISA program (Financial Services Agency) and standard Japanese tax-reporting guidance for individual investors.