Calculators & Number Tools
Find the right calculator for everyday arithmetic, date planning, work schedules, conversions, programming, and number formatting.
Everyday calculations
Calculate percentages, units, scientific expressions, ages, and dates.
- Percentage Calculator - Calculate percentages, percentage change, reverse percentages, and more
- Unit Converter - Convert between units of length, weight, temperature, volume, speed, area, data, and time
- Scientific Calculator - Calculate radian trig, logarithms, powers and remainders with recent history
- Age Calculator - Compare a birth date with an as-of date in calendar years, months and days
- Date Calculator - Compare calendar dates or add and subtract days, months and years
Dates, schedules, and goals
Plan countdowns, ranges, work hours, calendar events, and tracked habits.
- Date Countdown Calculator - Save up to 25 event targets and display the active countdown with optional sound
- Date Range Calculator - Calculate the exact number of days, weeks, months, or years between two dates
- Work Hours Calculator - Add shift hours and breaks, estimate weekly overtime and export CSV
- Add to Calendar Link Generator - Prepare provider draft links or one calendar event file with validated times
- Free Online Habit Tracker & Goal Planner - Track your habits, build daily streaks, and view progress with GitHub-style heatmaps
Developer and number utilities
Convert bases, estimate tokens, format numbers as words, or solve specialized sums.
- Number Base Converter - Convert numbers between binary, octal, decimal, and hexadecimal instantly
- Token Calculator - Count text with local encodings or community tokenizers
- Numbers to Words Converter - Convert numbers, decimals, and currency amounts into English words
- Roman Numerals Converter - Convert standard numbers to Roman numerals and translate Roman numerals to base-10 integers
- Cross Sum Calculator - Add decimal digits and follow each step to a digital root
- Vanity Number Calculator - Convert keypad letters to digits and find complete matches from 40 example words
- Counter Online - Manage up to 25 browser tallies with whole-number steps and optional targets