Math Tools

Balance chemical equations by entering reactants and products in standard notation — uses Gaussian elimination for accurate integer coefficients. Free online chemical equation balancer.

Simulate AND, OR, NOT, NAND, NOR, XOR, XNOR, and BUFFER logic gates with real-time output, truth tables, and Boolean expressions — up to 8 gates simultaneously. Free online logic gate simulator.

Calculate Total Daily Energy Expenditure from age, height, weight, and activity level using the Mifflin-St Jeor equation — get BMR, maintenance calories, goal targets, and macros. Free online TDEE calculator.

Calculate voltage, current, resistance, or power from any two known electrical values — supports all 6 input combinations and SI prefixes (kΩ, mA, μW). Free online Ohm's Law calculator.

Solve for speed, distance, or time from any two known values — 6 speed units, 7 distance units, 5 time units, cross-unit conversions, and human-readable time output. Free online speed distance time calculator.

Calculate the molecular weight of any chemical formula using IUPAC 2021 atomic weights. Supports all 118 elements, parentheses, brackets, and hydrate notation — Free online molecular weight calculator.

Convert any date and time from one timezone to multiple timezones simultaneously with automatic DST handling — supports 80+ IANA timezones. Free online timezone converter.

Look up what any time zone abbreviation means — full name, UTC offset, DST status, and disambiguation notes for 90+ abbreviations across all regions. Free online time zone reference.

Browse all country and territory flag emojis with ISO codes, Unicode codepoints, HTML entities, and CSS values — search by country name or code and copy with one click. Free online flag emoji reference.

Reference guide for binary, octal, decimal, and hexadecimal number systems with examples, digit rules, and instant cross-base lookup. Free online number system reference.

Calculate sunrise, sunset, solar noon, and day length for any date and location using the NOAA solar position algorithm — supports polar day and polar night. Free online day length calculator.