All in One Smart Calculator

A clean, easy-to-use calculator app with all the features you actually need. From everyday quick math to scientific expressions and unit conversions — everything fits in one app. ■ Calculator Features • Basic operations, percentage, sign toggle • Scientific mode: sin, cos, tan, log, ln, √, x², x^y, π, e, parentheses • Expression mode: enter multi-step formulas on a single line • Memory functions (M+, M-, MR, MC) • Auto-detect numbers from the clipboard for quick paste • Backspace (delete one digit at a time) • Thousands separators shown automatically as you type (for example, 100000 shows as 100,000), applied to results too ■ Handy Tools • Tip Calculator — auto-calculate tip and per-person amount from any bill • Discount Calculator — percentage or fixed amount; see savings and final price • Split the Bill — exclude separately-paid amounts, then divide by headcount • Unit Price Comparison — compare price per 100g / 100mL / unit for items A and B • Unit Converter — 8 categories: length, weight, temperature, speed, area, volume, time, data • Time Zone Calculator — set one city's time and compare cities worldwide at a glance (50+ cities, automatic DST, works offline) • Date Calculator — date difference, add or subtract dates, age calculation ■ Formula Library (interactive) • 71 formulas across 5 fields: geometry, finance and daily life, trigonometry and algebra, physics and engineering, astronomy • Pick a formula and enter values to calculate instantly — not just a reference chart, but a tool where your input gives an answer • For geometry, your values appear live on the matching sides, radius, or height of the shape • See your entered numbers substituted into the formula in real time • Each formula includes a usage help and an explanation of what it is, its origin, and history (in all 9 languages) • Handles multiple results (the two roots of a quadratic, a circle's area and circumference, and more), and shows a notice when there is no real solution or a division by zero • Very large or small values are shown in scientific notation (such as 1.5 x 10^11) ■ History & Favorites • All calculations saved automatically • Mark favorites and filter to show only favorites • Delete entries individually or all at once • Export results as text ■ Tax & Finance Tools (shown by your country of residence) Set your country in Settings under Region — separate from your display language — and the matching tools appear automatically. • Japan — Consumption Tax (net and tax-included both ways, 10%/8%/custom, rounding modes), Simplified Taxation, Invoice Transitional Relief, the 20% Special Rule, and Marketplace Profit • China / Germany / Spain / France — VAT calculator: convert both ways with each country's standard rates plus a custom rate (CN 13/9/6/3%, DE 19/7%, ES 21/10/4%, FR 20/10/5.5/2.1%) • Korea — payroll suite: net pay, four major insurances, severance, VAT, compound interest, savings interest, annual leave • Reference-only note on first open, with a help guide in every tool ■ Personalization • Light and dark mode toggle • 7 accent color choices • Haptic feedback and optional button sounds • Portrait and landscape, optimized for iPhone and iPad ■ Privacy • No ads, no tracking, no data collection • No external network calls • No permission prompts at launch • All data (history, memory, settings) stays on your device ■ Languages • Available in 9 languages: Korean, English, Japanese, Chinese (Simplified and Traditional), German, Spanish, French, Portuguese (Brazil) • Follows your system language automatically, with manual switching in-app A clean look and dependable features to make your everyday quick math feel better.