Units & Numbers Tools

One converter for everything: length, weight, volume, temperature, area, speed, pressure, energy, power, and data — with live results as you type.

Convert temperatures between °C, °F, K, and °R with exact formulas — including the two points where scales meet (e.g. -40°C = -40°F).

Solve everyday percentage problems: X% of Y, X as a percentage of Y, and the percentage change between two values.

Convert bytes, kilobytes, megabytes, gigabytes, terabytes — with both decimal (1000) and binary (1024) interpretations shown side by side.

Convert between 30+ currencies using manual or pasted rates — fully offline, no live-rate API, with a rate table you control.

Convert meters, kilometers, miles, feet, inches, yards, nautical miles, and more — instantly and with plenty of precision.

Convert kg, g, lbs, oz, stones, tons, and other mass units with exact factors — handy for recipes, fitness, and shipping.

Convert liters, milliliters, gallons (US/UK), quarts, pints, cups, fluid ounces, cubic meters, and more — including cooking volumes.

Convert m², km², ft², yd², acres, hectares, and other area units — useful for real estate, construction, and land measurement.

Convert km/h, mph, knots, meters per second, feet per second, and Mach — perfect for travel, weather, and aviation.

Convert bar, psi, Pa/kPa/MPa, atmospheres, mmHg, torr, and inHg — for engineering, diving, and weather applications.

Convert joules, kilocalories, kilowatt-hours, BTUs, and electronvolts — for nutrition, physics, and electricity billing.

Convert W, kW, MW, horsepower (metric/mechanical), and BTU/h — for appliances, engines, and electrical systems.

Convert temperatures between °C, °F, K, and °R with exact formulas — including the two points where scales meet (e.g. -40°C = -40°F).

One converter for everything: length, weight, volume, temperature, area, speed, pressure, energy, power, and data — with live results as you type.

Convert bytes, kilobytes, megabytes, gigabytes, terabytes — with both decimal (1000) and binary (1024) interpretations shown side by side.

Convert network speeds — Mbps, Gbps, MB/s, KiB/s — with the bits-vs-bytes distinction made explicit (1 MB/s = 8 Mbps).

Convert between cups, tablespoons, teaspoons, fluid ounces, and grams — with ingredient-aware density so 1 cup of flour ≠ 1 cup of sugar.

Convert shoe sizes across US, UK, EU, and mondopoint (cm) systems for men's, women's, and kids' shoes.

Convert clothing sizes (S, M, L, XL…) across US, UK, EU, and international standards for tops and bottoms.

Convert any number 1–3999 to Roman numerals (and back), with validation and the subtractive-notation rules applied.

Convert large and small numbers to and from scientific notation (1.5 × 10³) with configurable significant digits.

Convert fractions to decimals and decimals back to simplified fractions — with mixed numbers and repeating-decimal detection.

Solve everyday percentage problems: X% of Y, X as a percentage of Y, and the percentage change between two values.

Simplify any ratio to its lowest terms, solve for an unknown term (a:b = c:?), and convert ratios to percentages.

Convert any number up to 999 trillion into English words — great for writing checks, invoices, and accessibility.

Parse English number phrases ('one million two hundred thousand') into numeric form — the inverse of Number to Words.

Count the significant figures in any number (zeros included, leading zeros excluded) and round to a target number of sig figs.

Round any number to N decimal places or to a chosen precision step (nearest 0.5, 5, 10, 100…), with half-up and half-even modes.

Generate one or many random integers or decimals within a range — with an optional no-duplicates mode and copy-ready output.

One converter for everything: length, weight, volume, temperature, area, speed, pressure, energy, power, and data — with live results as you type.

Convert temperatures between °C, °F, K, and °R with exact formulas — including the two points where scales meet (e.g. -40°C = -40°F).

Convert meters, kilometers, miles, feet, inches, yards, nautical miles, and more — instantly and with plenty of precision.

Convert kg, g, lbs, oz, stones, tons, and other mass units with exact factors — handy for recipes, fitness, and shipping.

Convert liters, milliliters, gallons (US/UK), quarts, pints, cups, fluid ounces, cubic meters, and more — including cooking volumes.

Convert m², km², ft², yd², acres, hectares, and other area units — useful for real estate, construction, and land measurement.

Convert km/h, mph, knots, meters per second, feet per second, and Mach — perfect for travel, weather, and aviation.

Convert bar, psi, Pa/kPa/MPa, atmospheres, mmHg, torr, and inHg — for engineering, diving, and weather applications.

Convert joules, kilocalories, kilowatt-hours, BTUs, and electronvolts — for nutrition, physics, and electricity billing.

Convert W, kW, MW, horsepower (metric/mechanical), and BTU/h — for appliances, engines, and electrical systems.

Convert bytes, kilobytes, megabytes, gigabytes, terabytes — with both decimal (1000) and binary (1024) interpretations shown side by side.

Convert network speeds — Mbps, Gbps, MB/s, KiB/s — with the bits-vs-bytes distinction made explicit (1 MB/s = 8 Mbps).

Convert between 30+ currencies using manual or pasted rates — fully offline, no live-rate API, with a rate table you control.

Convert between cups, tablespoons, teaspoons, fluid ounces, and grams — with ingredient-aware density so 1 cup of flour ≠ 1 cup of sugar.

Convert shoe sizes across US, UK, EU, and mondopoint (cm) systems for men's, women's, and kids' shoes.

Convert clothing sizes (S, M, L, XL…) across US, UK, EU, and international standards for tops and bottoms.

Convert any number 1–3999 to Roman numerals (and back), with validation and the subtractive-notation rules applied.

Convert large and small numbers to and from scientific notation (1.5 × 10³) with configurable significant digits.

Convert fractions to decimals and decimals back to simplified fractions — with mixed numbers and repeating-decimal detection.

Solve everyday percentage problems: X% of Y, X as a percentage of Y, and the percentage change between two values.

Simplify any ratio to its lowest terms, solve for an unknown term (a:b = c:?), and convert ratios to percentages.

Convert any number up to 999 trillion into English words — great for writing checks, invoices, and accessibility.

Parse English number phrases ('one million two hundred thousand') into numeric form — the inverse of Number to Words.

Count the significant figures in any number (zeros included, leading zeros excluded) and round to a target number of sig figs.

Round any number to N decimal places or to a chosen precision step (nearest 0.5, 5, 10, 100…), with half-up and half-even modes.

Generate one or many random integers or decimals within a range — with an optional no-duplicates mode and copy-ready output.