複利・積立計算
複利と毎月積立で将来価値を概算（ローカル）。
Interactive controls load with JavaScript. Processing stays in your browser—nothing is uploaded.
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How to use
- Open the calculator — Open Compound Interest & DCA.
- Enter assumptions — Set principal, rate, compounding frequency, and optional contributions.
- Review estimate — Read the projected value. Note the ordinary-annuity assumption.
- Compare carefully — Treat results as estimates—not bank or investment advice.
Limits
Educational model only. Ignores many bank fees, taxes, and day-count conventions. Not investment advice.
When to use
Explore how rate, time, and contributions change an estimate—privately in the browser.
When not to use
When you need official statements, tax filings, or regulated advice.
Privacy note
Numbers are calculated locally and not uploaded.
FAQ（5）
Is this investment advice?
No. Results are estimates for education only, not investment, tax, or credit advice.
Which compounding frequencies are supported?
Monthly, quarterly, and annual compounding, depending on the options on the page.
Ordinary annuity assumption?
Recurring contributions are modeled as an ordinary annuity (end of each period), which may differ from your bank’s day-count or fee rules.
Why might a bank app disagree?
Banks may use different day counts, fees, rounding, or compounding conventions. Use their statements as the source of truth for real products.
Is calculation uploaded?
No. All math runs in your browser.