Furusato Nozei

給与収入や課税所得からふるさと納税の寄附上限額(自己負担2,000円の目安)を計算する。ふるさと納税、寄附上限、寄附金控除、ワンストップ特例の相談に対応。API不要の純粋計算。確定申告書の作成や個別の税務判断は対象外。

Install

skills CLI (Claude Code, Cursor, Codex and more)

npx skills add tahodev/kurashi-skill --skill furusato-nozei

Manual install

git clone --depth 1 https://github.com/tahodev/kurashi-skill.git /tmp/kurashi-skill
mkdir -p ~/.claude/skills
cp -r /tmp/kurashi-skill/furusato-nozei ~/.claude/skills/furusato-nozei

Personal skills live in ~/.claude/skills. Use .claude/skills in a project folder to share a skill with your team.

From the SKILL.md

# furusato-nozei

ふるさと納税で「自己負担2,000円で済む寄附額の上限」の目安を計算するスキル。外部APIは使わず、公開されている計算式だけで求める。

## 上限額の計算式

```
上限額 = 個人住民税所得割額 × 20% ÷ (90% − 所得税率 × 1.021) + 2,000円
```

この式は総務省「ふるさと納税のしくみ - 税金の控除について」の控除計算(住民税の特例分の上限 = 住民税所得割額の20%)から導かれるもの。
根拠: https://www.soumu.go.jp/main_sosiki/jichi_zeisei/czaisei/czaisei_seido/furusato/mechanism/deduction.html (2026年9月時点で確認)

- **個人住民税所得割額**: 課税所得 × 10% で概算できる(標準税率の場合)。正確な値は住民税の決定通知書に載っている。
- **所得税率**: 課税所得(所得税ベース)に応じて下表。

下表は **2026年9月時点の現行値** (令和7年4月1日現在の法令に基づく国税庁の公表値。平成27年分以降から変更なし)。
根拠: 国税庁 No.2260「所得税の税率」 https://www.nta.go.jp/taxes/shiraberu/taxanswer/shotoku/2260.htm

| 課税所得(所得税) | 所得税率 |
| --- | --- |
| 195万円以下 | 5% |
| 195万円超 330万円以下 | 10% |
| 330万円超 695万円以下 | 20% |
| 695万円超 900万円以下 | 23% |
| 900万円超 1,800万円以下 | 33% |
| 1,800万円超 4,000万円以下 | 40% |
| 4,000万円超 | 45% |

1.021 は復興特別所得税分。

## 給与収入から課税所得を概算する

利用者が課税所得を知らない場合は、給与収入から概算する。

1. **給与所得控除** を引く(下表は **2026年9月時点の現行値** = 令和7年分以降。令和7年度税制改正で最低保障額が55万円→65万円に引き上げられた):
   - 190万円以下: 65万円
   - 190万円超 360万円以下: 収入 × 30% + 8万円
   - 360万円超 660万円以下: 収入 × 20% + 44万円
   - 660万円超 850万円以下: 収入 × 10% + 110万円
   - 850万円超: 195万円(上限)

   根拠: 国税庁 No.1410「給与所得控除」 https://www.nta.go.jp/taxes/shiraberu/taxanswer/shotoku/1410.htm (2026年9月時点で確認)
2. 給与所得 = 給与収入 − 給与所得控除
3. 課税所得 ≈ 給与所得 − 所得控除(基礎控除、社会保険料控除、配偶者控除、扶養控除など)

Read the full skill on GitHub

Details

Skill name: furusato-nozei
Repository: tahodev/kurashi-skill
Path: furusato-nozei/SKILL.md
License: MIT
Repo updated: 29 October 2026
Listed in: karanb192/awesome-claude-skills

FAQ

What does the Furusato Nozei skill do?

How do I install the Furusato Nozei skill?

skills CLI (Claude Code, Cursor, Codex and more): npx skills add tahodev/kurashi-skill --skill furusato-nozei. Skills go in ~/.claude/skills (personal) or .claude/skills (project), and Claude loads them automatically when a task matches the description.

Is Furusato Nozei popular?

It lives in tahodev/kurashi-skill, which has 4 GitHub stars and 2 forks, and is included in 1 curated skill list.

Related skills

Glb Buildings

hec-ovi/glb-buildings-skill

Generate building GLBs for Unreal Engine, Unity and three.js by editing a named project through the `buildings` CLI. Stacks of floor bands become one validated glTF file, cheap enough to place by the thousand, with a blueprint preview the human can click. Use whenever the user wants to create, edit, rebuild or preview a building, a tower, a facade, a city block, or a GLB of any structure.

Software Development

Disk Jockey

bmcreations/disk-jockey

Diagnose and safely reclaim disk space on developer machines filled by AI agents, worktrees, builds, simulators, emulators and toolchain caches (Xcode, Android/Gradle, Node, Docker, Python, Rust, Go). Use when disk is low or filling fast, builds fail with "No space left on device", kernel_task shows huge disk writes, or the user asks to clean up storage.

Software Development

Roast

janderswag/roast-skill

The free Roast & Rebuild Claude Code skill. Runs a 6-module audit on the current local repository — Roast, Security, Architecture, Customer Flow, Growth, Founder Briefing. Every finding cites file:line evidence. Same opinionated voice as the paid $19 audit at roastrebuild.com. Use when: "roast my repo", "audit this", "what's wrong with my code", "security check", "what should I fix next".

Software Development

Codify

anombyte93/codify

Refactor any skill by extracting deterministic operations into a Python script and slimming the SKILL.md to only AI judgment parts. Use when user says /codify, codify a skill, or optimize a skill.

Software Development

Xsoar Pack Dev

mdrobniu/xsoar-pack-dev-skill

Cortex XSOAR content pack development lifecycle - create packs, integrations, scripts, playbooks, run demisto-sdk lint/validate/pre-commit, build zip packs, manage versions and release notes, run unit tests, deploy to XSOAR instances, manage git branches/tags, handle marketplace vs local pack workflows. Use when the user wants to develop, test, build, validate, deploy, or manage XSOAR content packs.

Software Development

Ynm

RobLe3/ynm-skill

Evidence-backed project and repository review for implementation correctness, architecture, specification-versus-code conflicts, tests-versus-documentation, release or production readiness, adoption, maintenance, security claims, and conflicting project evidence. Enter through lightweight YNM-0 routing, preserve unresolved evidence as MAYBE, and escalate only when additional work can materially improve the disposition.

Software Development

Browse the most popular Claude skills, all software development skills, or write your own with the skills generator.