OmniCalcsConversion Calculators
Free unit converters for length, weight, temperature, area, volume, speed and more.
Length Converter
Convert between 12 units of length.
Weight Converter
Mass units from grams to tons and ounces.
Temperature Converter
Celsius, Fahrenheit, Kelvin and Rankine.
Area Converter
Square meters, acres, hectares and more.
Volume Converter
Liters, gallons, cups and tablespoons.
Speed Converter
km/h, mph, knots and Mach number.
Time Converter
Seconds to years and everything between.
Energy Converter
Joules, calories, kWh and BTU.
Data Storage Converter
Bits to terabytes with clear sizing.
Pressure Converter
Pascal, bar, psi, atm and mmHg.
Angle Converter
Degrees, radians, gradians and turns.
Frequency Converter
Hz to GHz with wavelength display.
Fuel Economy Converter
mpg, L/100km and km/L conversions.
Power Converter
Watts, kW, HP and BTU/hr conversions.
About Conversion Calculators
Free unit converters for length, weight, temperature, area, volume, speed and more.
Every tool runs entirely in your browser — instant results, no sign-up, no data sent to any server. All formulas are standard and published so you can verify the math yourself.
Frequently Asked Questions
Are these tools really free?
Yes. Every conversion tool on OmniCalcs is 100% free with no registration, and always will be.
Do I need to install anything?
No. All calculators run in your browser with pure HTML, CSS and JavaScript — nothing to download.
How accurate are the results?
Each tool uses standard, published formulas shown on its page, so you can verify every result yourself.