Japan FIRE calculator

Calculate your monthly savings to reach FIRE in Japan.

Choose a preset or set a custom target. Adjust returns, timeline, and current assets to see your required savings. Export to CSV anytime.

Client-side only 4% default return CSV export

Presets

Select FIRE Target

Assumes 4% net return. Select a preset or use Custom.

Inputs

Assumptions & Scenario

Adjust return rate, timeline, and current assets.

Visualizations

Your FIRE Journey

Interactive charts showing asset growth and returns breakdown.

Current Progress

1.5%

of target reached

Final Portfolio

¥66,000,000

in 30 years

Total Returns

¥32,031,450

94% of contributions

Asset Growth Timeline

Loading Chart...

Shows how your portfolio grows over time from initial investment, monthly contributions, and compound returns.

Contributions vs Returns

Loading Chart...

Visualizes the power of compound returns. Over time, investment returns typically surpass your contributions.

Results

Required Monthly Savings

Based on your inputs and current investments.

Years order:

Years range:MinMaxStep

Invested range (M JPY):MinMaxStep

Rows show years remaining; columns show current invested assets in million JPY. Adjust the ranges above to explore any portion of the sheet.

How many years to reach your goal? Years you have left	0 M Current investments	1 M Current investments	5 M Current investments	10 M Current investments	15 M Current investments	20 M Current investments	25 M Current investments	30 M Current investments	35 M Current investments	40 M Current investments	45 M Current investments	50 M Current investments
5	¥995,490	¥977,074	¥903,408	¥811,325	¥719,243	¥627,160	¥535,077	¥442,995	¥350,912	¥258,830	¥166,747	¥74,664
10	¥448,218	¥438,093	¥397,595	¥346,973	¥296,350	¥245,728	¥195,105	¥144,482	¥93,860	¥43,237	✓ Target reached!	✓ Target reached!
15	¥268,194	¥260,797	¥231,210	¥194,225	¥157,241	¥120,256	¥83,272	¥46,288	¥9,303	✓ Target reached!	✓ Target reached!	✓ Target reached!
20	¥179,947	¥173,887	¥149,648	¥119,349	¥89,050	¥58,751	¥28,452	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!
25	¥128,372	¥123,094	¥101,980	¥75,589	¥49,197	¥22,805	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!
30	¥95,094	¥90,320	¥71,223	¥47,353	¥23,482	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!
35	¥72,231	¥67,804	¥50,093	¥27,954	¥5,815	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!
40	¥55,839	¥51,660	¥34,942	¥14,046	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!
45	¥43,724	¥39,728	¥23,745	¥3,766	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!	✓ Target reached!

Invested: 0M

Column 1 / 12

Years RemainingValue

5 Years¥995,490

10 Years¥448,218

15 Years¥268,194

20 Years¥179,947

25 Years¥128,372

30 Years¥95,094

35 Years¥72,231

40 Years¥55,839

45 Years¥43,724

Rounded to the nearest ¥1,000 equivalent. Monthly compounding with end-of-month deposits.

Legend

Lower monthly savingHigher monthly saving

Rows = years remaining. Columns = already invested amount (million JPY).
Use the range filters above the sheet to focus on the bands that matter to you.
Units respect your selection (`10K ¥` or `¥`).
Hover or focus a cell to see the exact yen amount and the scenario inputs.

Note: Calculations assume the "4% Rule" (Trinity Study) as a baseline for safe withdrawal rates. Actual results depend on market performance, inflation, and tax rates.

Formula

How the calculator works

We treat contributions as end-of-month deposits, compounding monthly at net rate r = (P/100)/12 over n = years × 12 months.

M = (T - S(1 + r)^n) / (((1 + r)^n - 1) / r)

Excel / LibreOffice PMT reference:

=PMT(rate/12, years*12, -current_invested, target)

Example: with T = ¥66M, S = ¥25M, P = 4%, and Y = 15, the result is ≈ ¥83,000/month (rounded to the nearest thousand and clamped to zero if negative).

Notes

Assumptions & caveats

Returns are net of fees/taxes and compound monthly; tweak the rate slider to reflect your outlook.
“man” units assume ¥10,000 per unit. Switch units any time to match how you think about cash flow.
Negative monthly savings are shown as zero and represent scenarios where your existing investments already meet the target.
You can export rounded table values plus precise (pre-rounded) yen via the CSV download button.
All calculations happen client-side; no inputs leave your browser.