Convert between decimal, hex, binary and octal with ASCII view.
Convert numbers between decimal, hexadecimal, binary and octal instantly, plus an ASCII decoder for any hex or binary byte string.
100% client-side — zero uploads, maximum privacy
Instant results — no waiting for server processing
Secure — your data never leaves your browser
Free to use — no sign-up required
Real-time calculation as you type — no submit button needed
Step-by-step breakdowns for full transparency
Amortization schedules, unit conversions, and health formulas
Bookmarkable results for quick reference
Works offline after initial page load
Perform base converter tasks directly in your browser
Save time with instant, server-free processing
Maintain full privacy — your data never leaves your device
Get reliable results powered by well-tested algorithms
Use it anywhere — no installation or account required
Values are processed as unsigned integers up to 2^53-1 — fine for everyday conversions.
Percentage of, percentage change and percentage increase/decrease.
Monthly payment, total interest and full amortization schedule.
Length, weight, temperature, data, area, volume, time and speed conversion.
Exact age in years, months, days, plus days until your next birthday.
Days between dates, add/subtract days from a date, weekday lookup.
Body Mass Index with healthy-range guidance.