Unit converters
546 unit converters: length, weight, temperature, volume, speed, pressure, energy, data and cooking measures. Type a value, pick the units and get an exact result with the conversion factor shown, free in your browser.
Momentum converter
Convert linear momentum between kg·m/s, g·cm/s and lb·ft/s: 10 kg·m/s is 1000000 g·cm/s. Compare an SI textbook value with an older cgs lab manual or a US…
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Running pace converter
Restate one running pace on every common scale: 5 minutes per kilometer is 12 km/h, 8.04672 minutes per mile and 7.45645430685 mph, so a metric race plan and an…
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Paper size dimensions
Get the exact size of any common sheet before you print or design: A4 is 210 × 297 mm, or 8.26771653543 × 11.6929133858 inches, with the same pairing for…
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Paper weight converter
Find out that 20 lb bond paper is about 75 gsm, or go the other way, for text, bond, cover and index stock.
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Power converter
1000 watts is 1.3410220896 mechanical horsepower. Switch between watts, kilowatts, megawatts, horsepower, BTU per hour and foot-pounds per second for motor…
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PPM percent converter
1000 ppm is 0.1 %, 1 % is ten thousand ppm and 1 ppm is 1000 ppb. Enter one concentration and see it at once in ppm, ppb, percent and per-mille, so labels, lab…
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Radiation exposure converter
Turn survey-meter readings into SI units and back: 1 roentgen is exactly 0.000258 C/kg and 1 milliroentgen is a thousandth of a roentgen, so logs and quizzes…
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Radioactivity converter
Move an activity reading between becquerels, curies and rutherfords with every common prefix: one curie is exactly 3.7 × 10¹⁰ becquerels, so assay certificates…
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Electrical resistance converter
Convert resistance across five decades of units with fixed SI factors: 1000 Ω is exactly 1 kΩ, so milliohm shunts, kilohm pull-ups and gigaohm insulation…
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Electrical resistivity converter
Put resistivity from any table into the unit you need: copper's 1.68 × 10⁻⁸ Ω·m becomes 1.68 µΩ·cm, and wire-table values in ohm circular-mil per foot map…
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Ring size converter
Enter the ring size you know and see it in every system: a US 7 is a UK O, an EU 54 and an inside diameter of about 17.35 mm, with the circumference worked out…
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Roof pitch converter
Translate one roof pitch into the other notations: a 6/12 roof is about 26.57 degrees and a 50 % slope, so framing plans, inspection notes and drainage specs…
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Shoe size converter
Enter one shoe size, its scale and men's or women's, and get the other three: a men's US 9 is a UK 8, an EU 41.91 and a 27.94 cm last length, so ordering abroad…
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Slope grade converter
A 10% grade is a 1:10 rise over run and about 5.71 degrees, not 10. Enter one slope as a percent, an angle or a ratio and get the other two, for road plans…
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Solid angle converter
One steradian is 3282.8063500117 square degrees. Convert a solid angle between steradians, square degrees, spat and fractions of a sphere when a datasheet and a…
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Sound pressure level converter
One pascal is about 94 dB SPL and 20 micropascals is 0 dB. Convert sound pressure between pascals, micropascals and decibels SPL, or a pressure ratio into…
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Specific energy converter
1 kJ/kg is 0.239005736138 cal/g. Convert energy per unit mass between J/kg, kJ/kg, thermochemical calories per gram and BTU per pound when a problem set, a fuel…
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Specific heat capacity converter
4184 J/(kg·K) is exactly 1 cal/(g·°C). Convert a specific heat capacity between joules per kilogram-kelvin, calories per gram-degree Celsius and BTU per…
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Specific volume converter
1 m³/kg is 1000 L/kg. Convert volume per unit mass between cubic metres per kilogram, litres per kilogram and cubic feet per pound when a steam-property note…
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Speed converter
10 m/s is 36 km/h. Convert a speed between metres per second, kilometres per hour, miles per hour, knots and feet per second for road limits, sailing logs, wind…
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Surface tension converter
72.8 mN/m is exactly 72.8 dyn/cm and 0.0728 N/m. Convert surface tension between N/m, mN/m, dyn/cm and lbf/ft when water-like values near 72 mN/m meet older…
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Thermal conductivity converter
1 W/(m·K) is 0.5777893165 BTU/(h·ft·°F). Move a material's conductivity between SI datasheets, older US insulation literature and CGS calorie tables, always…
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Thermal resistance converter
1 K/W is 0.52752792631 °F·h/BTU, and 1 °C/W is exactly 1 K/W. Convert a thermal resistance between heatsink datasheets, SI models and imperial insulation…
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Time unit converter
90 seconds are 1.5 minutes, 0.025 hours or 90,000 milliseconds. Convert a duration between seconds, minutes, hours, days, weeks, milliseconds and microseconds…
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Torque converter
50 N·m is 36.878107463863 lbf·ft. Convert torque between newton-metres, newton-centimetres, pound-force feet, pound-force inches and kilogram-force metres, with…
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Screen size converter
A 55-inch 16:9 screen measures 139.7 cm diagonally, about 121.75910254 cm wide and 68.48949518 cm high.
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Points to pixels converter
12 points are 16 CSS pixels. Convert type sizes between points, pixels and picas with the CSS rule of 96 pixels and 72 points per inch, to move print specs from…
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PX to EM converter
24 px is 1.5 em when the parent font size is 16 px. Convert CSS lengths between pixels and em in either direction against the parent font size, and get a…
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px to rem converter
With a 16 px root, 16 px is 1 rem and 0.5 rem is 8 px. Convert CSS lengths between pixels and rem against the root font size your stylesheet actually sets, and…
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Voltage converter
5 V is 5000 mV. Convert an electric potential between volts, millivolts, microvolts, kilovolts and megavolts with exact SI prefixes, and get the factor and…
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Volume converter
Move a recipe, a packing list or a lab procedure between metric and US volume units: one US gallon is 3.785411784 liters, and every conversion passes through…
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Water hardness converter
Put a city water report and a softener manual on the same scale: one grain per gallon is 17.1 ppm and one German degree is 17.8 ppm, and every reading bridges…
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Wire gauge converter
Turn an AWG number into real dimensions: 12 AWG, the usual branch-circuit copper, measures 2.052525388494 mm across.
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Base36 encoder
255 in base 36 is 73: this converter turns whole numbers into short codes made of digits and the letters A to Z, and decodes them back to decimal.
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BCD converter
42 in 8421 BCD is 0100 0010: each decimal digit gets its own group of four bits, unlike pure binary.
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Binary to decimal converter
1010 in binary is 10 in decimal: enter any run of zeros and ones and get the base-ten number, with each place worth a power of two. Free in your browser.
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Decimal to hex converter
255 in decimal is ff in hexadecimal: enter a whole number and get its base-16 form, with each hex digit standing for four bits, ready for colour codes, logs or…
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Engineering notation converter
12345.6 becomes 12.3456 × 10³, or 12.3456 k: engineering notation keeps the exponent a multiple of three so values line up with SI prefixes on schematics…
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Greek numeral converter
2024 in Ionic Greek numerals is ͵βκδʹ: a left keraia and beta for the thousands, kappa for twenty, delta for four.
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Percent to fraction converter
40% is 2/5 once 40/100 is divided by its greatest common divisor, 20. Decimal and negative percentages work too, and you see the unreduced fraction beside the…
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Roman fraction converter
Seven twelfths of an as is S·, the septunx: S for half plus one dot for an uncia. Enter any count from 0 to 12 for the Roman mark, its Latin name and the…
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Significant figures rounder
1234.567 to three significant figures is 1230, also shown as 1.23e+3. Keep only the digits your measurement supports, with exact halves rounded away from zero…
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Acres to square meters converter
One international acre is exactly 4,046.8564224 square metres. The converter multiplies your acreage by that full figure, not the rounded 4,047, so imperial…
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Physical action converter
1 joule-second is 10,000,000 erg-seconds. This converter moves physical action between J·s, eV·s, erg·s, N·m·s and the Planck constants h and ħ, and shows each…
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Water alkalinity converter
One dKH from an aquarium test kit equals 17.848 mg/L as calcium carbonate. The converter moves alkalinity between eight units, including meq/L, ppm, French and…
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Angular momentum converter
1 kg·m²/s is 10,000,000 g·cm²/s. The converter moves angular momentum between six units, from joule-seconds and newton-metre-seconds to erg-seconds and pound…
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API gravity converter
A 35-degree crude has a specific gravity of 0.84984984985 and a density of 849.013597597598 kg/m³.
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ATM to PSI converter
1 atm is 14.695948775513 psi, not a rounded 14.7. This converter turns standard-atmosphere readings from textbooks or European data sheets into the pounds per…
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Beaufort scale converter
Force 5, a fresh breeze, is 18.168656007245 knots. Convert wind between the Beaufort scale and knots, mph, m/s, km/h or ft/s in either direction, with the…
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Belt size converter
A 34-inch waist takes a size 36 belt: the belt number runs two inches above the waist so the buckle closes on the middle hole.
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Binary prefix converter
1 MiB is 1.048576 MB, not 1 MB: the converter keeps kibi, mebi and gibi apart from kilo, mega and giga with exact powers of two and ten, so a disk label and a…
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BTU to kWh converter
One BTU is 0.00029307107 kWh, worked out from the exact International Table definition rather than a rounded rule of thumb.
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Calories to joules converter
One calorie is exactly 4.184 joules under the thermochemical definition, the constant chemistry and thermodynamics courses expect.
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Calorific value converter
38 MJ/m³ of pipeline gas is just under one thousand twenty BTU per cubic foot. Switch any calorific value among seven volume-based units used in gas contracts…
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CM to inches converter
2.54 cm is exactly one inch, so the converter divides your centimeters by 2.54 and shows each step, ready to check clothing size charts, DIY cut lists or…
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Color depth converter
24 bits per pixel give 16,777,216 colors: convert color depth between bits per pixel, number of colors, bits per channel, bytes per pixel and levels per…
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Cubic meters to cubic feet converter
1 cubic meter is about 35.314666721489 cubic feet: convert metric volumes from SI drawings and tank specs into the cubic feet printed on US HVAC plates, crate…
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Degrees to gradians converter
A right angle of 90° is exactly 100 gradians. Enter degrees and get gons with the exact ten-ninths factor, anchored on a full turn of 360° being 400 gradians…
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Didot point converter
12 Didot points, one cicero, measure 4.512 mm. Convert between Didot points, ciceros, millimetres, centimetres, PostScript points, picas and inches, so a…
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Electric flux converter
One statvolt centimetre equals 2.99792458 volt metres. Convert electric flux between V·m, N·m²/C, kilovolt and millivolt metres, C/ε₀ and statV·cm, for…
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