株式ナンピン計算機

株式ナンピン(難平)計算機。追加購入時の新しい平均取得単価、収益率の変化、総投資額を即座に計算します。

Stock Average Down Calculator — the fastest way to plan your next stock purchase. When your stock drops, should you buy more? This calculator instantly shows you the impact of averaging down: your new average price, return rate change, and total investment needed. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📊 CORE CALCULATOR (Free) • Enter your average purchase price, current price, and shares owned • Slide to adjust additional shares and see results update in real time • View before/after return rates side by side • New average price, total shares, total investment, and additional cost — all at a glance ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🎯 TARGET AVERAGE CALCULATOR (Free) Set your goal. Get the exact number. "I want my average down to $130 — how many shares do I need?" Just enter your target average price, and the calculator instantly tells you: • Exact number of shares to buy • Total investment required No more guessing with the slider. Plan your purchase with precision. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📋 PORTFOLIO TRACKER (Free: 3 / Pro: Unlimited) Save your stocks. Track them all in one place. • Save calculations with a custom name (e.g., "AAPL", "TSLA") • See return rates at a glance in the portfolio list • Tap to load — instantly restore all values • Delete anytime • Data persists across sessions Free users can save up to 3 stocks. Upgrade to Pro for unlimited saves. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📈 SCENARIO SIMULATOR (Pro) What if the price drops another 20%? What if it bounces 10%? Compare three scenarios side by side: • Bear (-20%) — worst case • Moderate (-10%) — likely dip • Bull (+10%) — recovery Each scenario shows the new price, new average, and return rate if you buy the same additional shares at that price. Plan your strategy before committing. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 💱 MULTIPLE CURRENCIES (Pro) Calculate in your local currency: • USD ($) — Free • KRW (₩), JPY (¥), EUR (€), GBP (£), CNY (¥), INR (₹), BRL (R$) — Pro Each currency has proper formatting: decimal handling, thousand separators, and locale-specific display. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🌍 8 LANGUAGES English, 한국어, 日本語, 简体中文, 繁體中文, Deutsch, Español, Português Auto-detects your browser language. Switch anytime from the popup. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🌙 DARK MODE Follows your system preference automatically. No setup needed. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚡ WHY THIS EXTENSION? • Instant — no sign-up, no login, no account needed • Private — all calculations stay on your device • Lightweight — under 50KB, no external scripts • Persistent — your inputs and portfolio are saved automatically • Clean UI — designed for quick decisions, not clutter ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 💎 FREE vs PRO FREE: ✓ Core calculator ✓ Target average calculator ✓ Portfolio (up to 3 stocks) ✓ USD currency ✓ 8 languages ✓ Dark mode PRO ($1.49/mo or $13.49/yr — 25% off): ✓ Everything in Free ✓ Scenario simulator ✓ 7 additional currencies ✓ Unlimited portfolio saves ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Perfect for retail investors who average down on stocks and want a quick, private, no-nonsense tool to plan their next move.