GoodLogoIt
HomeBinaryWeb DevText ToolsImage ToolsScreen SimsPrompts

Free Unit Converter Tools Online

Free online unit converters covering 25+ measurement types. Convert between metric and imperial units for length, weight, temperature, speed, area, volume, time, and more — all with instant results and formulas shown.

The metric (SI) and imperial systems coexist across engineering, science, cooking, construction, and everyday life. This converter suite handles the most common conversions and some specialised ones: from metre/foot to Celsius/Fahrenheit, kg/lbs to BTU/kWh. Every converter shows the conversion formula alongside the result so you can understand and verify the calculation.

Length ConverterConvert meters, feet, inches, km, miles, cm, yards, and more.Weight ConverterConvert kg, lbs, grams, ounces, tonnes, stones, and more.Temperature ConverterConvert Celsius, Fahrenheit, Kelvin, and Rankine with formulas.Area ConverterConvert sq m, sq ft, acres, hectares, sq km, and sq miles.Volume ConverterConvert liters, gallons, ml, cups, fl oz, pints, m³, and more.Speed ConverterConvert mph, km/h, m/s, knots, and Mach number.Time ConverterConvert seconds, minutes, hours, days, weeks, months, years.Digital Storage ConverterConvert bytes, KB, MB, GB, TB. Supports SI and binary standards.Currency ConverterConvert between 150+ world currencies with live exchange rates.Pressure ConverterConvert PSI, bar, pascal, kPa, atm, torr, and mmHg.Energy ConverterConvert joules, kWh, calories, kcal, BTU, and electron volts.Angle ConverterConvert degrees, radians, gradians, and turns.Frequency ConverterConvert Hz, kHz, MHz, GHz, RPM, and radians/second.Power ConverterConvert watts, kilowatts, horsepower, and BTU/hour.Torque ConverterConvert Nm, lb-ft, lb-in, and kg-m.Voltage ConverterConvert volts, millivolts, kilovolts, and microvolts.Current ConverterConvert amperes, milliamperes, and microamperes.Electric Charge ConverterConvert coulombs, mAh, Ah, and microcoulombs.Number to Roman NumeralsConvert any integer (1–3,999) to Roman numeral format.Roman Numerals to NumberDecode any Roman numeral string to a decimal integer.Each ConverterConvert between pieces, dozens, pairs, gross, and scores.Pace ConverterConvert running pace between min/km and min/mile.Parts Per ConverterConvert ppm, ppb, ppt, and percentage concentration.

Frequently Asked Questions

How do I convert Celsius to Fahrenheit?

°F = (°C × 9/5) + 32. Example: 100°C = (100 × 9/5) + 32 = 212°F. Use the Temperature Converter for instant results.

How many kilograms are in a pound?

1 pound = 0.453592 kg. 1 kg = 2.20462 pounds. Use the Weight Converter for instant conversion of any amount.

How many miles in a kilometre?

1 km = 0.621371 miles. 1 mile = 1.60934 km. Use the Length Converter for any distance.

Which unit converters show conversion formulas?

All converters on GoodToolIt show the conversion formula alongside the result, so you can understand how the calculation works.