Everyday & Shopping

Calculate exact age and day difference from birth date with timezone aware handling.

Flip a coin online with 3D animation, multi-coin mode, decision helper, and session statistics — powered by cryptographic randomness.

Unified countdown timer and stopwatch with up to 10 concurrent timer cards, natural-language input, serialized alarm queue, local restore, cross-tab sync, voice announcements, custom preset editor (drag-reorder, color-coded, shareable link), 15 ready presets (Pomodoro, Tabata, egg, ramen, meditation, meeting), multi-step engine, Web Audio bells, Wake Lock, fullscreen big display, and shareable URL. Timers run in the current browser with no login required and do not rely on a LittleOne Tools timer backend.

Calculate date differences, date offsets, business-day offsets, and lookup ISO week, quarter, leap year, lunar, zodiac, and solar-term details.

Calculate exact age and day difference from birth date with timezone aware handling.

Flip a coin online with 3D animation, multi-coin mode, decision helper, and session statistics — powered by cryptographic randomness.

Unified countdown timer and stopwatch with up to 10 concurrent timer cards, natural-language input, serialized alarm queue, local restore, cross-tab sync, voice announcements, custom preset editor (drag-reorder, color-coded, shareable link), 15 ready presets (Pomodoro, Tabata, egg, ramen, meditation, meeting), multi-step engine, Web Audio bells, Wake Lock, fullscreen big display, and shareable URL. Timers run in the current browser with no login required and do not rely on a LittleOne Tools timer backend.

Calculate date differences, date offsets, business-day offsets, and lookup ISO week, quarter, leap year, lunar, zodiac, and solar-term details.

Find the day number for any date, reverse-lookup a day number to its date, and view a full year calendar table with progress bar, ISO week, and quarter info.

Calculate discount amount, sale price, and savings online.

Free online electronic signature pad: handwrite with mouse / finger / stylus, with Apple Pencil pressure, palm rejection, quadratic Bézier smoothing + velocity-responsive stroke width, stroke-level undo/redo (including undoable clear), three brushes (pen / marker / highlighter), three preset colors + custom. Export transparent PNG @1x/@2x/@3x, white-background JPG, or vector SVG (auto-trimmed bounding box with optional padding), copy to clipboard. Browser-local, no uploads, no login.

Check if a year is a leap year, list leap years in a range, with step-by-step rule verification and statistics.

Bidirectional conversion between Gregorian and Chinese lunar calendar (1900-2100). Four modes: single-day lookup (three-pillar Ganzhi, zodiac, lunar month names, precise solar-term times), 6×7 month grid (dual-labeled Gregorian + lunar + solar term + festival), batch conversion (multi-line paste or CSV / JSON upload, up to 1000 rows), and annual lookup of 18 lunar festivals + 24 solar terms. Handles leap-month disambiguation, .ics calendar download, and URL share links. Client-side computation, no app backend, no login.

Calculate X% of Y, find percentage share, reverse a percent, and measure percentage change.

Paste a list and one click covers name picking, prize draws and team grouping. Your data is not uploaded by the tool.

Free online reaction-speed self-test: Simple RT (tap when signal turns green), Choice RT (4-color choice response), and Go/No-Go (respond to green, not red). Configurable 3 / 5 / 10 / 20 trials, sub-millisecond timing with double-rAF baseline, false-start detection, MAD-based outlier rejection, median / SD / IQR statistics, and 6-tier neutral performance banding. Mobile-first (touch-action manipulation, full-screen tap zone, ≥72px targets), fully bilingual, keyboard-accessible, reduced-motion aware, optional 30-day local history, setup-only share URLs, PNG result poster export. Browser-local — no login, default no ad scripts, default no third-party analytics, no upload. For entertainment and personal reference only; not a medical, psychological, or neurological assessment, and not a substitute for professional driver-license testing.

Calculate tip amount, per-person split, and total bill online.

Local workday calculator: 5-market statutory holidays (CN/US/UK-EW/UK-SCT/UK-NIR/HK/JP, 2023-2027) + State Council 调休 / EO 11582 observed rule + custom holidays + 3 modes (count between dates / add-subtract / classify single day) + Excel NETWORKDAYS.INTL / WORKDAY.INTL compatibility + 17 weekend codes + 14-day calendar strip + fail-closed URL share. Mobile 44px touch-first. No login, default no ad scripts, default no third-party analytics.