Instant, Accurate
Unit Conversion Tools
Convert length, weight, temperature, cooking recipes, fuel economy, and 20 measurement categories with zero clutter and instant accuracy.
Enter any number above to convert Millimeters to Centimeters. Click (i) for brief unit info.
Popular Conversions
Direct access to our most frequently used calculators
Feet to Meters Converter
Convert length or height from feet (ft) to meters (m) with exact international conversion factors.
Meters to Feet Converter
Convert distance and elevation from metric meters (m) to imperial feet (ft) instantly.
Kilograms to Pounds Converter
Convert mass and body weight from kilograms (kg) to pounds (lbs) with exact avoirdupois ratios.
Pounds to Kilograms Converter
Convert weight from imperial pounds (lbs) to metric kilograms (kg).
Celsius to Fahrenheit Converter
Convert temperature from degrees Celsius (°C) to Fahrenheit (°F) with exact thermodynamic formulas.
Fahrenheit to Celsius Converter
Convert degrees Fahrenheit (°F) to Celsius (°C) for cooking, meteorology, and science.
Inches to Centimeters Converter
Convert length and dimensions from inches (in) to centimeters (cm) with exact precision.
Centimeters to Inches Converter
Convert metric centimeters (cm) to imperial inches (in) for engineering, clothing sizes, and drafting.
Miles to Kilometers Converter
Convert driving and geographic distances from statute miles (mi) to kilometers (km).
Acres to Square Feet Converter
Convert land and property acreage to square feet (sq ft) with exact legal surveyor precision.
Liters to Gallons Converter (US Liquid)
Convert metric liters (L) to US liquid gallons with accurate fluid measurement standards.
MPG to L/100 km Converter (US Gallons)
Convert vehicle fuel efficiency between US Miles per Gallon and Liters per 100 Kilometers with exact reciprocal formulas.
Comprehensive Unit Categories
Every major physical and scientific measurement standard organized into dedicated conversion modules.
Length & Distance
Convert between metric and imperial distances including millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles.
Weight & Mass
Convert mass and weight measurements including milligrams, grams, kilograms, metric tons, ounces, pounds, stones, and tons.
Area & Surface
Convert planar surface areas with mathematically squared ratios including square meters, square feet, acres, hectares, and square kilometers.
Volume & Capacity
Convert cubic dimensions and liquid capacities across metric, US customary, and UK Imperial standards without mixing standards.
Temperature
Accurate thermal conversion across Celsius, Fahrenheit, and Kelvin utilizing precise physical thermodynamic formulas.
Speed & Velocity
Convert speed and velocity rates between meters per second, kilometers per hour, miles per hour, feet per second, knots, and Mach.
Pressure & Stress
Convert atmospheric, hydrostatic, and mechanical pressures across Pascal, kPa, bar, PSI, standard atmospheres, and Torr.
Energy & Work
Convert energy values between Joules, kilojoules, scientific calories, dietary kilocalories, Watt-hours, kilowatt-hours, and BTUs.
Power & Heat Flow
Convert power ratings across Watts, kilowatts, megawatts, mechanical horsepower, metric horsepower, and BTU per hour.
Time & Duration
Convert durations between milliseconds, seconds, minutes, hours, days, weeks, standard months, and years with explicit calendar assumptions.
Data Storage & Memory
Convert digital storage sizes strictly distinguishing decimal SI standards (1 KB = 1000 B) from binary IEC standards (1 KiB = 1024 B).
Cooking & Baking
Beginner-friendly kitchen measures with support for ingredient density when converting between volume (cups, spoons, mL) and mass (grams, ounces).
Angle & Geometry
Convert planar angles with mathematical precision across degrees, radians, gradians, arcminutes, and arcseconds.
Force & Thrust
Convert force and thrust measurements across Newtons, kilonewtons, dynes, kilogram-force, and pound-force.
Torque & Rotational Moment
Convert mechanical torque and twisting force between Newton-meters, Newton-centimeters, pound-feet, pound-inches, and kgf-meters.
Density & Specific Mass
Convert material density across kilograms per cubic meter, grams per cubic centimeter, grams per milliliter, and pounds per cubic foot.
Fuel Economy & Consumption
Convert vehicle mileage and consumption rates properly handling the inverse reciprocal relationship between MPG and L/100km.
Acceleration
Convert linear acceleration rates between meters per second squared, km/h per second, feet per second squared, and standard Earth gravity (g).
Frequency & Wave Cycles
Convert cyclic rates across Hertz, kilohertz, megahertz, gigahertz, and rotational revolutions per minute (RPM).
Number Base (Radix)
Convert whole numerical representations between Binary (base 2), Octal (base 8), Decimal (base 10), and Hexadecimal (base 16) with character validation.
Engineered for Mathematical Reliability
Unlike generic calculator pages that rely on crude approximations, ConvertUnitTools enforces rigorous precision standards across all operations.
Exact Conversion Factors
We implement standard SI and imperial unit definitions, ensuring linear factors (like 1 in = 2.54 cm exact) have zero rounding drift.
Float Jitter Elimination
Standard JavaScript floating-point errors (e.g., 0.30000000000000004) are stripped via precision-normalization so you always see clean, legible results.
Physical Curve Modeling
Non-linear measurements (reciprocal fuel economy curves, thermodynamic affine temperature shifts, binary vs decimal data) are modeled with their true physical laws.