Sumbox - Calculator & Tools

Sumbox: all your everyday math, in one box.

Calculate, convert, plan, and split the bill without hunting for another tool. Get a Basic and Scientific calculator plus 30+ free tools. No ads, no sign-up, and calculation history stays on your device. Available in English, Simplified Chinese, and Traditional Chinese.

CALCULATOR • Basic and Scientific modes, landscape support, and a distraction-free Focus Mode • Decimal-exact arithmetic: 0.1 + 0.2 = 0.3 • Percent, repeated equals, automatic closing parentheses, and implicit multiplication • Up to 15 significant digits, thousands separators, and easy-to-read large-number labels • Tap a number or operator in the expression to select and replace it, then press equals to recalculate • Memory keys, Reuse from History, and text or CSV history export

30+ TOOLS • Conversion: Currency Converter (19 currencies, reference rates cached for offline use), Unit Converter (12 categories, including traditional Chinese units) • Finance: RMB in Chinese Numerals, China Income Tax (pay, bonuses, and annual reconciliation), China Retirement Age (statutory age, retirement month, minimum contribution years, and flexible retirement range under China mainland rules; for reference only), Equal Payments, Equal Principal, Compound Growth, Savings Goal, Installment True APR • Everyday: Chinese Family Titles (up to 12 relationship steps, with Chinese titles, pinyin, and English explanations), Chinese Converter (Simplified ↔ Traditional Chinese, five calligraphy styles, and image sharing), Sunrise & Sunset (offline sunrise, sunset, twilight, and golden hour; no location access), Discount (Chinese 折 discounts), Split the Bill, Tip & Split, Compare Unit Prices, Date Difference, Date Calculator, Age Calculator (with Chinese zodiac and zodiac sign), Random Numbers • Health & Travel: BMI (Chinese adult reference ranges), Running Pace, Fuel Cost • Math: Percent, Percent Change, Circle Area, Right Triangle • Developer: Hash Calculator (including HMAC), Number Base Converter (including two’s complement), Base64 Encode/Decode, Timestamp Converter, Password Generator, UUID Generator

THEMES Mint and Clear Contrast are always free. Six premium themes—Rice Paper & Ink, Retro LCD, Cyber Neon, Cream Macaron, Deep Space OLED, and Kraft Ledger—bring their own colors, key shapes, fonts, sounds, and matching app icons. Try any theme in full before buying. Unlock All Themes is an optional one-time purchase with Family Sharing and includes themes added later.

PRIVACY No accounts, ads, analytics, or tracking. History stays on your device; delete or export it at any time. Currency requests send currency codes, never entered amounts. Optional update checks ask the App Store for public app information and can be disabled in Settings.

Exchange rates are reference rates; your bank’s or platform’s quote applies. Financial calculations are not financial advice. China Income Tax applies to China mainland resident individuals’ comprehensive income. China Retirement Age applies to China mainland employees and is subject to local authorities’ determination. Both are estimates for reference only. Check context-dependent Chinese conversions. BMI reference ranges are not a medical diagnosis.

Privacy Policy: https://suanhe.timesoria.com/en/privacy/ Terms of Use: https://suanhe.timesoria.com/en/terms/

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