New NISA Accumulation Simulator

Tracks, year by year, how the annual investment frames for the Tsumitate (accumulation) and Growth investment frames and the shared lifetime tax-free holding cap (with a sub-cap for the Growth frame) are consumed, and models both over-limit contributions and frame reuse after a sale.

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Calculation basis and official references

Reviewed on:

Formula basis

Each month, the Tsumitate frame receives the smaller of the requested monthly contribution, the remaining annual Tsumitate frame (up to 1.2 million yen/year), or the remaining shared lifetime cap (up to 18 million yen). The Growth frame receives one lump-sum contribution at the start of each simulated year, capped by its own annual limit (2.4 million yen/year), the remaining shared lifetime cap, and its own lifetime sub-cap (up to 12 million yen within the 18 million total), and is consumed before the Tsumitate frame each year. Investment gains are non-taxable and compound monthly at one-twelfth of the assumed annual rate. A single optional sale can be specified; the sold book-value amount, once confirmed within that year's held balance for the chosen frame, restores that much lifetime frame capacity (and Growth sub-cap capacity, if sold from the Growth frame) starting the following year, matching the official reuse rule.

Calculation method

Models Japan's new NISA (tax-free investment account, in effect since January 2024) as a monthly/annual accumulation simulation. Because investment gains are tax-free, no tax calculation is performed; instead the calculator tracks, year by year, how the annual investment frames for the Tsumitate and Growth frames and the shared lifetime tax-free holding cap (with a 12-million-yen sub-cap for the Growth frame) are consumed.

Exclusions and checks required

  • The Growth frame is modeled as a single lump-sum purchase at the start of each year and is consumed before the Tsumitate frame; this is a simplification and does not represent any specific brokerage's actual purchase timing or frame-consumption order.
  • Only one sale (frame-reuse) event can be modeled per simulation. The sold amount is assumed to reduce the balance by exactly its book value, without modeling unrealized gains or losses or lot-level cost-basis averaging (e.g. the moving-average method).
  • The assumed annual rate of return is a user-supplied assumption and is not a guarantee of future investment performance or of any specific product's return. Fees, trust fees, dividend reinvestment timing, foreign exchange effects, and future tax-law changes are not modeled.
  • The statutory limits for the selected year are held fixed for the entire simulation horizon; in reality these could change in a future tax reform (see the statutory review trigger).
  • A new age-based Tsumitate frame sub-category for investors aged 0-17 (planned to start in fiscal 2027, with a 600,000 yen/year limit and a 6 million yen lifetime cap) is out of scope for this calculator, which models only the standard NISA account for investors aged 18 and over.

Example input:：Example: 50,000 yen/month via the Tsumitate frame plus 200,000 yen/year via the Growth frame, over 20 years at an assumed 5% annual return

year
2026
monthlyTsumitateMan
5
growthAnnualMan
20
years
20
annualRate
5
rounding
floor
withdrawalYear
0
withdrawalBookValueMan
0
withdrawalFrame
tsumitate

The displayed balance is a projection based on the assumed rate of return and does not guarantee any actual investment outcome or any specific product's return.

Official references

FAQ

Who is this calculator for? New NISA Accumulation Simulator

Tracks, year by year, how the annual investment frames for the Tsumitate (accumulation) and Growth investment frames and the shared lifetime tax-free holding cap (with a sub-cap for the Growth frame) are consumed, and models both over-limit contributions and frame reuse after a sale.

What values should I enter?

Applies to: Accumulation / The Tsumitate frame invests monthly and the Growth frame invests once a year, each up to its annual limit and the shared lifetime cap (with the Growth frame also capped by its own sub-limit), compounding tax-free.

How should I interpret this estimate?

Models Japan's new NISA (tax-free investment account, in effect since January 2024) as a monthly/annual accumulation simulation. Because investment gains are tax-free, no tax calculation is performed; instead the calculator tracks, year by year, how the annual investment frames for the Tsumitate and Growth frames and the shared lifetime tax-free holding cap (with a 12-million-yen sub-cap for the Growth frame) are consumed.

How to use

  1. Enter your input values and press Calculate.
  2. Review the result and compare it with expected context.
  3. Each month, the Tsumitate frame receives the smaller of the requested monthly contribution, the remaining annual Tsumitate frame (up to 1.2 million yen/year), or the remaining shared lifetime cap (up to 18 million yen). The Growth frame receives one lump-sum contribution at the start of each simulated year, capped by its own annual limit (2.4 million yen/year), the remaining shared lifetime cap, and its own lifetime sub-cap (up to 12 million yen within the 18 million total), and is consumed before the Tsumitate frame each year. Investment gains are non-taxable and compound monthly at one-twelfth of the assumed annual rate. A single optional sale can be specified; the sold book-value amount, once confirmed within that year's held balance for the chosen frame, restores that much lifetime frame capacity (and Growth sub-cap capacity, if sold from the Growth frame) starting the following year, matching the official reuse rule.

Official references