Converters
Convert between the units Americans use day to day: inches and centimeters, pounds and kilograms, Fahrenheit and Celsius, and more. Every converter shows both directions and a quick reference chart.
127 free tools in this category. See every tool on Lelifi.
- 12 Hour to 24 Hour Converter CalculatorConvert 12 hour clock times to 24 hour time and back. The 12 AM and 12 PM rules,
- Acres to Hectares ConverterConvert acres to hectares and back with the exact NIST factor: 1 acre = 0.404685
- Acres to Linear Feet CalculatorConvert acres to linear feet and perimeter. A 1-acre square has 208.71-foot side
- Acres to Square Feet ConverterConvert acres to square feet and sq ft to acres instantly. 1 acre equals exactly
- Activation Energy CalculatorFind activation energy from two rate constants and temperatures with the two poi
- Air Density CalculatorFind air density from temperature, pressure, humidity or altitude in kg/m3 and l
- Amps to Watts CalculatorConvert amps to watts for DC, single phase and three phase AC. Enter current, vo
- Angle ConverterConvert any angle between degrees, radians, gradians, turns, arcminutes, arcseco
- Angle of Depression CalculatorFind the angle of depression from a height difference and a level distance, or w
- Angle of Elevation CalculatorEnter rise and run to get the angle of elevation in degrees, plus grade percent
- Area CalculatorFind the area of a rectangle, circle, triangle, trapezoid or parallelogram in sq
- Area ConverterConvert square feet, square meters, acres, hectares and square miles with exact
- BPM to FPS CalculatorConvert beats per minute to frames per second for animation timing. Enter BPM an
- BPM to Hz CalculatorConvert BPM to Hz and back. 120 BPM is 2 Hz, 90 BPM is 1.5 Hz, and 140 BPM is 2.
- BPS to Hz CalculatorConvert bits per second to hertz for any modulation. Nyquist bandwidth, baud rat
- BTU per Hour to Tons ConverterConvert BTU per hour to tons of cooling by dividing by 12,000, with tables, squa
- Billions to Trillions ConverterConvert billions to trillions and back: 1 trillion is 1,000 billion on the short
- Celsius to Fahrenheit ConverterFree Celsius to Fahrenheit converter. Type °C and get °F instantly (F = C × 9/5
- Celsius to Kelvin ConverterConvert Celsius to Kelvin by adding 273.15, with a chart for 0, 25, 37 and 100 °
- Celsius to Rankine ConverterConvert Celsius to Rankine with the exact formula: multiply by 9/5 and add 491.6
- Centimeters to Inches ConverterConvert centimeters to inches instantly. 1 cm = 0.3937 in. Free converter with a
- Conversion CalculatorConvert length, weight, volume, temperature and speed with exact factors: inches
- Coterminal Angle CalculatorFind coterminal angles in degrees or radians: normalize into 0 to 360, list the
- Days Until CalculatorCount the days until any date, with weeks, business days and US federal holidays
- Density CalculatorFind density from mass and volume, or get the weight of water, concrete, steel o
- Density ConverterConvert density between kg/m3, g/cm3, kg/L, lb/ft3, lb/in3 and lb per gallon in
- Dimensional Analysis CalculatorConvert length, mass, pressure, speed and more with exact NIST factors, and see
- Diopter to mm CalculatorTurn diopters into focal length in mm and inches, add stacked close-up filters,
- Displacement CalculatorFind displacement from speed and time, or from acceleration, in meters, miles, f
- Double Angle CalculatorGet sin 2 theta, cos 2 theta and tan 2 theta from any angle in degrees or radian
- Draw Length CalculatorEstimate bow draw length from your wingspan with both standard formulas, convert
- Fahrenheit to Celsius ConverterFree Fahrenheit to Celsius converter. Enter °F and get °C instantly (C = (F − 32
- Fahrenheit to Kelvin ConverterConvert Fahrenheit to kelvin with K = (°F - 32) × 5/9 + 273.15. 32 °F is 273.15
- Fahrenheit to Rankine ConverterConvert Fahrenheit to Rankine by adding 459.67. 32 °F is 491.67 °R and 212 °F is
- Fahrenheit: The Scale, Its History and Its ConversionsWhat the Fahrenheit scale is, why water freezes at 32 F and boils at 212 F, who
- Feet to MPH CalculatorConvert feet per second to mph and mph to feet per second instantly. 1 ft/s = 0.
- Feet to Meters ConverterConvert feet to meters instantly. 1 foot = 0.3048 m exactly. Free converter with
- Feet to kg CalculatorConvert length in feet to weight in kilograms for rebar, steel pipe, wire, and b
- GB to MB ConverterConvert GB to MB instantly: 1 GB = 1,000 MB (decimal) or 1 GiB = 1,024 MiB (bina
- GSM to MM CalculatorTurn paper GSM into thickness in mm, microns, mils or points. Bulk ranges for co
- Gallons to Cubic Feet ConverterConvert gallons to cubic feet and back: one cubic foot holds 7.48 US gallons, wi
- Gauge to mm CalculatorConvert AWG wire and sheet steel gauge numbers to millimeters, inches and square
- Gibbs Free Energy CalculatorEnter delta H, delta S and a temperature to get delta G, the verdict on spontane
- Gram to Pound ConverterConvert grams to pounds with the exact 453.59237 factor, plus kilograms and ounc
- Grams to OuncesConvert grams to ounces with the exact 28.349523125 g per ounce factor, plus tro
- Half Angle CalculatorHalve any angle and get sin, cos and tan of the half angle, with the sign picked
- Horsepower to Kilowatts ConverterFree hp to kW converter. Type mechanical horsepower and get kilowatts instantly
- How Many Steps in a MileWork out steps per mile from your height and pace. A 5 foot 7 walker takes about
- IP Address ConverterConvert an IPv4 address between dotted decimal, a 32-bit integer, hex, binary an
- Inch to Meter ConverterConvert inches to meters with the exact 0.0254 factor, including fractional inch
- Inches to Centimeters ConverterFree inches to cm converter. Type any length in inches and see the exact value i
- Inches to MilesConvert inches to miles with the exact 63,360 factor, plus feet, yards and kilom
- Inches to Yards ConverterConvert inches to yards by dividing by 36, with cut list, sewing and garden exam
- Inverting Buck-Boost Converter CalculatorSize an inverting buck-boost converter: duty cycle, inductor value, peak current
- Katha to Square Feet ConverterConvert katha to square feet and square feet to katha. Pick Bihar, West Bengal,
- Kelvin to Celsius ConverterConvert kelvin to Celsius by subtracting 273.15, with the answer rounded the way
- Kelvin to Fahrenheit ConverterConvert kelvin to Fahrenheit with both formulas, see the Celsius waypoint, and g
- Kelvin to Rankine ConverterConvert kelvin to Rankine by multiplying by 1.8. Enter any K or °R value for the
- Kilobytes to Megabytes ConverterConvert KB to MB with both the 1,000 and 1,024 scales side by side, so you can m
- Kilograms to Pounds ConverterFree kg to lbs converter. Type kilograms and get pounds instantly (1 kg = 2.2046
- Knots to MPH ConverterFree knots to mph converter. Type knots and get miles per hour instantly (1 knot
- Length ConverterConvert meters, feet, inches, miles, kilometers, yards and nautical miles with e
- Lowercase to Uppercase ConverterThis lowercase to uppercase converter switches text to UPPER, lower, Title Case,
- MPG to L/100km ConverterFree mpg to L/100km converter. Enter US mpg and get liters per 100 km instantly
- Mass CalculatorConvert mass between kilograms, grams, pounds, ounces, stone and tons, see the p
- Mbps to MB/s ConverterConvert Mbps to MB/s in one step: divide by 8. See your real download speed, how
- Mechanical Energy CalculatorAdd kinetic and potential energy in one step: ME = 0.5mv^2 + mgh, with an option
- Meter to Inch ConverterConvert meters to inches with the exact 39.3701 factor, plus feet and inches, th
- Meter to Yard ConverterConvert meters to yards with the exact 0.9144 factor. 100 m is 109.3613 yards, 1
- Meters to Feet ConverterFree meters to feet converter. Enter meters and get feet instantly, with a chart
- Meters to MilesConvert meters to miles with the exact factor 1,609.344, plus worked examples fo
- Metric Modulation CalculatorEnter an old tempo and two note values to get the new BPM, the reduced ratio, th
- Mile to MeterConvert miles to meters with the exact 1,609.344 factor, plus speed in km/h and
- Miles to InchesOne mile is exactly 63,360 inches. Convert any mile figure to inches, feet and y
- Miles to Yards ConverterConvert miles to yards with the exact 1,760 factor, a 0.1 to 10 mile chart, trac
- Million to Thousand ConverterConvert millions to thousands and back. One million is 1,000 thousand, so 2.5 mi
- Molar Mass CalculatorType any chemical formula to get its molar mass in g/mol, the uncertainty, the p
- Nautical Miles to Miles ConverterFree nautical miles to miles converter. Enter nautical miles and get statute mil
- Newton Meters to Foot-Pounds ConverterFree Nm to ft-lbs converter. Type newton meters and get foot-pounds instantly (1
- Ounce to GramsConvert ounces to grams with the exact 28.349523125 factor, plus troy ounces for
- Ounces to Pounds ConverterConvert ounces to pounds with exact numbers. 16 oz make 1 lb, so 26 oz is 1.625
- PSI to Bar ConverterFree psi to bar converter. Type psi and get bar instantly (1 psi = 0.0689476 bar
- Partial Pressure CalculatorFind the partial pressure of each gas in a mixture: enter the total pressure and
- Percent to Decimal CalculatorTurn a percent into the decimal you multiply by: 8.25% is 0.0825, 0.5% is 0.005
- Pint to Pound ConverterConvert pints to pounds by density. A US liquid pint of water weighs 1.04 lb, ho
- Pipe Volume CalculatorEnter the inside diameter and length of a pipe to get the water volume in gallon
- Population Density CalculatorDivide population by land area to get people per square mile or square kilometer
- Pounds to Grams ConverterConvert pounds to grams with the exact 453.59237 factor, plus kilograms, ounces,
- Pounds to Kilograms ConverterFree lbs to kg converter. Enter pounds and get kilograms instantly (1 lb = 0.453
- Pounds to Ounces ConverterConvert pounds to ounces with the exact 16 to 1 rule, plus the pounds and ounces
- Pounds to Tons ConverterConvert pounds to short tons, long tons and metric tonnes in one step, with exac
- Power CalculatorConvert power between watts, kilowatts, horsepower, BTU per hour, tons of refrig
- Power Factor CalculatorFind power factor from kW and kVA or from volts and amps on single and three pha
- Pressure CalculatorCalculate pressure three ways: force over area, depth with rho g h, or the ideal
- Pressure ConverterConvert psi, bar, kPa, MPa, atm, mmHg, inHg and kg per square centimeter with ex
- Rankine to Celsius ConverterConvert Rankine to Celsius in two steps: subtract 491.67, then multiply by 5/9.
- Rankine to FahrenheitConvert Rankine to Fahrenheit by subtracting 459.67, with worked examples for th
- Rankine to KelvinConvert degrees Rankine to kelvin by dividing by 1.8, with worked examples, a fi
- Rate Constant CalculatorFind the Arrhenius rate constant from A, activation energy and temperature, or s
- Reference Angle CalculatorFind the reference angle for any degree or radian measure, with the quadrant, th
- Scale CalculatorConvert a drawing, map, or model measurement into real size. Enter a scale ratio
- Shoe Size ConversionConvert shoe sizes between US men, US women, UK, EU and centimeters using the IS
- Speed CalculatorConvert mph, km/h, m/s, ft/s, knots and Mach in one step, read the speed as pace
- Speed Converter for mph, km/h, m/s, ft/s, Knots and MachConvert mph, km/h, knots, m/s, ft/s and Mach with exact NIST factors, see every
- Square Feet to Percentage CalculatorTurn any piece of a floor plan into a percent of the whole: 120 of 1,200 square
- Steps to Kilometers CalculatorConvert steps to kilometers using your height. At 5 foot 9, 10,000 steps is abou
- Steps to Miles CalculatorConvert steps to miles and kilometers using your height and walking pace. See yo
- Stone to Pounds ConverterTurn stone into pounds with the exact 14 factor, see 11 stone 4 broken down as 1
- Stone to Pounds ConverterFree stone to pounds converter. Type stones and get pounds instantly (1 stone =
- Surface Area CalculatorFind the surface area of a cube, box, sphere, cylinder, cone or pyramid in squar
- Tank Volume CalculatorTank volume calculator for rectangular and cylindrical tanks: enter dimensions a
- Temperature ConverterConvert one temperature into Celsius, Fahrenheit, kelvin and Rankine at once, pl
- Tons to Pounds ConverterConvert tons to pounds for all three tons: 2,000 lb short, 2,240 lb long, 2,204.
- Unit ConverterConvert length, weight, volume, temperature, area, speed, pressure, energy, data
- Unit Rate CalculatorTurn two quantities into a rate per one unit, then scale it to a bigger amount o
- Volts to Joules CalculatorConvert volts to joules from charge or from current and time, get capacitor ener
- Volume CalculatorEnter dimensions in inches, feet, centimeters or meters and get the volume of a
- Water Weight CalculatorConvert water volume to weight in pounds and kilograms using the density at your
- Watts to Amps CalculatorTurn watts into amps for DC, single phase AC and three phase AC, with power fact
- Wave Speed CalculatorConvert frequency and wavelength into wave speed in m/s, km/h and mph, with spee
- Weight Gain CalculatorPlan a muscle building surplus: enter a goal weight and get daily calories, the
- Weight Watchers Points CalculatorScore any food with the legacy Weight Watchers points formula: calories divided
- Yard to Meter ConverterConvert yards to meters with the exact 1959 factor: 1 yard = 0.9144 m. Instant t
- Yards to Inches ConverterConvert yards to inches with the exact 36. Eighth yard cuts from 4.5 to 31.5 inc
- Yards to Miles ConverterConvert yards to miles and back with the exact 1,760 yard mile. Get the formula,
- dBm to Watts ConverterConvert dBm to watts and milliwatts with the 10^(dBm/10) formula. Chart from -20
- kVA to Watts CalculatorConvert kVA to watts with the power factor: 1 kVA is 1,000 W at unity. Single an
Most of these converters exist because the United States measures in inches, pounds, miles and gallons while most of the rest of the world uses centimeters, kilograms, kilometers and liters. That gap shows up in ordinary places: a recipe from a British food blog lists grams, a European hotel site gives room size in meters, and a tire gauge reads in psi while the door sticker on a rental car might say bar.
The mistake that trips people up
Direction is the number one error. To go from pounds to kilograms you divide by 2.2, so a 200 lb suitcase is about 90.7 kg, not 440 kg. Going the other way you multiply. Speed has its own trap: internet plans are sold in megabits per second, but file sizes are shown in megabytes, and there are 8 bits in a byte. A 100 Mbps connection moves 12.5 MB/s, not 100, so a 5 GB file takes about 6 minutes 40 seconds rather than a few seconds.
- Storage: 1 GB is 1,000 MB in decimal terms, but an operating system that counts in 1,024 units will show a 1 TB drive as about 931 GB.
- Temperature: a quick estimate for Celsius to Fahrenheit is to double the number and add 30. For 20 C that gives 70, close to the exact 68 F.
- Pressure: tire gauges read gauge pressure, so 32 psi is 2.21 bar above atmosphere, not absolute.
- Torque: 1 N-m is 0.7376 ft-lb, and the two are often printed side by side on a wrench.
Every converter here works in both directions and shows a small reference chart, so you can sanity check the answer before you use it.