Data & Formats

Unit Converter

Convert one value between everyday physics and engineering units in the browser: meters and feet, kilograms and pounds, Celsius and Fahrenheit, psi and kPa, bar and atm, kWh and joules, mechanical horsepower and kilowatts, Mbps and MB/s, KB and KiB, radians and degrees, newtons and pound-force are all covered. 20+ categories span length, mass, duration, temperature, area, volume, speed, acceleration, pressure, energy, power, information, bit rate, frequency, angle, force, electric current, voltage, resistance, and density. Unit constants come from the UnitsNet generated dataset, so SI, imperial, and traditional definitions stay consistent. Parsing and formatting happen locally and no input is uploaded.

  • Metric / imperial side by side: meter ↔ foot, cm ↔ inch, kg ↔ pound, liter ↔ gallon, Celsius ↔ Fahrenheit in one panel
  • Pressure: Pa, kPa, MPa, bar, atm, psi, mmHg, and inHg listed together so tyre, weather, and industrial values cross-check at a glance
  • KB / MB / GB shown next to KiB / MiB / GiB, so a 1 TB drive showing 931 GiB stops being a mystery
  • Mbps, kbps, GB/s, and MB/s converted together so the 8× factor between bits and bytes is never missed again
  • Mechanical horsepower (~745.7 W), metric horsepower (~735.5 W), and boiler horsepower are separate rows so spec sheets do not blur together
tools/Unit Converter

Accepts decimals, negatives, and scientific notation such as 1.5e3.

Controls how many decimals each result keeps. Out-of-range values fall back to scientific notation.

Only common units are listed by default. Toggle on to see every unit in this category.

Enter a number and the equivalent in every unit will appear here.
Quick actions

Overview

Moving one quantity between several units shows up in API field alignment, hardware procurement, embedded work, capacity planning, cross-region collaboration, and everyday life. Grouping the common conversions into one panel with clear categories and adjustable precision removes the back-and-forth between scattered calculators.

  1. 01

    Length from nanometres to light-years

    Meter, kilometer, centimeter, millimeter, micrometer, nanometer, foot, inch, yard, mile, nautical mile, and light-year all live in the same panel. Meter to feet, cm to inches, and nautical miles to km drop out in one paste.

  2. 02

    Pressure: psi, bar, atm, mmHg in one table

    Pa, kPa, MPa, bar, mbar, atmosphere, Torr, psi, mmHg, and inHg are listed side by side. Tyre pressure between psi and bar, weather between hPa and mmHg, industrial drawings between kPa and MPa — no more three calculator tabs.

  3. 03

    Power: do not confuse hp variants

    Mechanical horsepower (~745.7 W), metric horsepower (~735.5 W), boiler horsepower, and electrical horsepower are separate rows. The hp on a US car spec and the PS on a European motor name plate now line up correctly, instead of drifting by ~1.4 %.

  4. 04

    Storage and bandwidth in parallel

    KB / MB / GB / TB and KiB / MiB / GiB / TiB are shown together so the gap between drive marketing and OS view is visible. Mbps, kbps, GB/s, and MB/s convert side by side, making 100 Mbps ≈ 12.5 MB/s obvious without the usual 8× math.

  5. 05

    Temperature formulas right in front of you

    Celsius, Fahrenheit, Kelvin, and Rankine convert together. °F = °C × 1.8 + 32 and K = °C + 273.15 are validated visually — useful for physics teaching, oven recipes, and importing US appliances.

  6. 06

    A complete set of electrical units

    Amperes, milliamperes, microamperes, kiloamperes; volts, millivolts, kilovolts; ohms, kilohms, megohms; hertz, kilohertz, megahertz, gigahertz — covers electronics datasheets, distribution panels, and spectrum diagrams.

How to use

From picking a category to copying the result, the whole flow lives in a single panel.

  1. 01

    Pick a category on the left — length, temperature, pressure, information, etc.

  2. 02

    Pick a source unit such as meter, Celsius, psi, or MB.

  3. 03

    Enter the number in the input. Decimals, negatives, and scientific notation (1.5e3, -273.15) are all accepted.

  4. 04

    On the right, every target unit shows its equivalent. Toggle Show all units when you need uncommon ones.

  5. 05

    Tune the decimal precision, then copy the value from the row you want with its per-row copy button.

Details

One panel covers the most useful physics and engineering conversions, with precision control and per-category lazy-loading for a fast first paint.

  • Length spans 28 orders of magnitude — from nanometres and micrometres to kilometres, nautical miles, and light-years
  • Mass covers grams, kilograms, metric tons, milligrams, micrograms, pounds, ounces, short tons, long tons, and stones
  • Temperature lists Celsius, Fahrenheit, Kelvin, and Rankine simultaneously
  • Area includes square metres, square kilometres, hectares, acres, square feet, and square inches
  • Volume covers cubic metres, cubic centimetres, liters, millilitres, US gallons, imperial gallons, oil barrels, plus US cups, tablespoons, and teaspoons
  • Speed converts between m/s, km/h, mph, ft/s, and knots (kn)
  • Pressure: Pa, kPa, MPa, bar, mbar, atm, Torr, psi, mmHg, and inHg in one pass
  • Energy: joule, kilojoule, megajoule, calorie, kilocalorie, watt-hour, kilowatt-hour, BTU, electron-volt, foot-pound
  • Power: watt, kilowatt, megawatt, gigawatt and four distinct horsepower definitions
  • Information: decimal KB/MB/GB/TB next to binary KiB/MiB/GiB/TiB
  • Bit rate: bps, kbps, Mbps, Gbps, Tbps and B/s, KB/s, MB/s, GB/s side by side
  • Electrical: ampere, volt, ohm, hertz with three or four orders of magnitude each
  • Angle: degree, radian, gradian, arcminute, arcsecond, revolution, and NATO mil
  • Force: newton, kilonewton, pound-force (lbf), kilogram-force (kgf), dyne
  • Density: kg/m³, g/cm³, g/mm³, lb/ft³, lb/in³
  • Precision: Auto, 2, 4, 6, or 12 decimals with automatic fallback to scientific notation
  • Input accepts 1.5e3, -42, and 1,234.5-style numbers
  • Each quantity is its own chunk and only loads on demand, so the initial JS stays light
  • Parsing and conversion run locally; no value ever leaves your browser

Use cases

The point of a converter is to remove the calculator-record-recheck loop. Below are the concrete scenarios where the tool earns its keep.

  1. API field unit alignment

    Is timeout in ms or seconds? Is size in bytes or MB? Is distance in metres or feet? Lock the primary unit early and put a quick conversion in the doc (30 s = 30000 ms, 5 MB = 5,242,880 B) to remove a whole class of integration bugs.

  2. Procurement: imperial ↔ metric specs

    Motor rated in hp → kW, tyre pressure in psi → bar, fastener torque in ft·lbf → spec sheets in N, temperatures in °F → °C, lengths in inch / foot → mm / m. Run one batch through the tool and your procurement sheet stays consistent.

  3. Embedded and electronics

    Move between mV / V / kV for rail voltages, mA / µA for quiescent current, Ω / kΩ / MΩ for dividers, Hz / kHz / MHz / GHz for clocks and PWM frequencies, all while reading a datasheet.

  4. Ops and capacity planning

    A 1 TB drive shows as ~931 GiB on Linux, a 1 Gbps link delivers ~125 MB/s of file throughput, memory and traffic quotas mix decimal and binary units. Pin the conversion in your sizing doc so dashboards and alerts use the same numbers.

  5. Weather and daily life

    US forecasts use °F, inHg, mph; the rest of the world uses °C, hPa / kPa, km/h, mmHg. Lay them out once so reading NOAA against a local feed stops needing mental math.

  6. Fitness, cooking, importing

    Body weight between pounds and kilograms, height between feet/inches (5 ft 9 in) and centimetres, recipes between US cups / tablespoons / teaspoons and millilitres, oven temperatures between °F and °C, fluid measures between US and imperial gallons.

  7. Research and writing

    Normalise inputs from different sources to SI (metre, second, kilogram, pascal, joule) before they reach a figure or table. Optionally show CGS (dyne, erg) or engineering units in a footnote for the reviewers.

  8. Teaching and slides

    Walk through scales — 1 atm = 101,325 Pa, 1 eV = 1.602×10⁻¹⁹ J, 1 light-year ≈ 9.461×10¹⁵ m — with a live panel instead of static slides.

See also

When you need to convert integers across binary, octal, decimal, and hex, keep using Number Base Converter . If you are working with time fields like Unix timestamps and human dates, reach for Timestamp Converter .

Best practices

Conversion itself is deterministic, but the way it lands in code, docs, and contracts is what decides whether downstream readers stay aligned.

  • Store and transport in SI (metres, seconds, kilograms, pascals, joules) and apply unit conversion only at the presentation layer; this avoids semantic drift between services.
  • Spell out the unit in API field names — timeoutMs, ttlSeconds, sizeBytes, distanceMeters — so consumers never have to guess.
  • Use IEC binary units (GiB, TiB, MiB/s) for storage capacity and OS-reported values; use SI decimal units (GB, TB, MB/s) for marketing capacity and bandwidth. Show the conversion once (1 TB = 0.909 TiB) and stick to a single convention per surface.
  • Annotate the 8× factor between bits and bytes when bandwidth and throughput sit on the same page (100 Mbps ≈ 12.5 MB/s, 1 Gbps ≈ 125 MB/s).
  • When a doc mixes hp values, always say which horsepower — mechanical (US, ~745.7 W) or metric (PS, ~735.5 W) — to keep ±1.4 % errors out of marketing copy.
  • Pin significant figures explicitly in scientific writing. 1.225 kg/m³ and 1.2 kg/m³ are both right at the right precision.
  • Prefer scientific notation for very large or very small values: 1.602e-19 reads faster than 0.0000000000000000001602 and removes the chance of miscounting zeros.

Limitations

The tool focuses on converting one quantity between units. Currency, exchange rates, compound math, temperature differences, and date arithmetic are out of scope.

  • No currency conversion — rates need a live data source, which conflicts with the local-first design.
  • No compound or cross-quantity math: m/s² × kg = N, or W × h = J. Use mathjs / Qty.js or a scientific calculator for that.
  • Temperature converts absolute scales only. A 10 °C change equals 10 K but only ~18 °F; if you need a delta, multiply manually by 1.8.
  • BTU has multiple definitions (IT, ISO, thermochemical); this tool uses the UnitsNet default International Table BTU. Cross-check the project docs if your spec requires a different one.
  • Math runs on JavaScript Number, so extreme values may carry floating-point error. Financial, legal-measurement, and dosage work should be double-checked with a dedicated precision tool.
  • Date and timestamp conversion lives in the dedicated timestamp tool. This tool only handles the duration quantity (seconds, milliseconds, minutes, hours, days, weeks, months, years).
  • No domain corrections — altitude-pressure compensation, temperature-corrected viscosity, humidity-adjusted dew point, and similar specialised conversions are not provided.

FAQ

These are the questions teams actually search for during procurement, embedded debugging, ops planning, research, and everyday life — answered with concrete numbers.

How do I convert psi to kPa?

1 psi ≈ 6.8948 kPa. So a 32 psi tyre pressure is about 220.6 kPa, and a 100 psi water line ≈ 689.5 kPa. The pressure category lists psi alongside Pa, kPa, bar, atm, and mmHg so you see all of them at once.

How many joules in a kilowatt-hour (kWh)?

1 kWh = 3,600,000 J = 3.6 MJ. A household kilowatt-hour from the electricity meter is the same energy used in heating efficiency or EV battery comparisons.

What is the difference between mechanical and metric horsepower?

Mechanical (imperial) horsepower ≈ 745.7 W and is common on US engine spec sheets. Metric horsepower (PS in German, ch in French) ≈ 735.5 W and is common on European and Asian vehicles. The two differ by about 1.4 %; this tool exposes them as separate rows so you do not pick the wrong one.

How do I convert Celsius to Fahrenheit?

Use °F = °C × 1.8 + 32 and °C = (°F − 32) ÷ 1.8. Useful values: 25 °C = 77 °F, 180 °C ≈ 356 °F (typical oven), 98.6 °F = 37 °C (body temperature), 0 °C = 32 °F (water freezing).

How do I convert Mbps to MB/s?

1 byte = 8 bits, so 100 Mbps ≈ 12.5 MB/s and 1 Gbps ≈ 125 MB/s. The Mbps on an ISP plan is a transmission rate; the MB/s in a download client is a file-system throughput — they differ by 8×.

What is the difference between KB and KiB, MB and MiB?

KB / MB / GB use decimal (SI): 1 KB = 1000 B, 1 MB = 1,000,000 B. KiB / MiB / GiB use binary (IEC): 1 KiB = 1024 B, 1 MiB = 1,048,576 B. A drive marketed as 1 TB therefore shows as ~931 GiB on Linux or Windows.

How many kilometres in a nautical mile?

1 nautical mile (nmi) = 1.852 km. A vessel doing 20 knots ≈ 37 km/h, and an airliner at 35,000 ft ≈ 10,668 m — both routinely need the nmi ↔ km mapping.

How many pascals in 1 atmosphere?

1 atm = 101,325 Pa = 101.325 kPa = 1.01325 bar = 760 mmHg ≈ 14.696 psi. Meteorology and chemistry usually report in hPa or atm.

How big is the US gallon compared to the imperial gallon?

US gallon ≈ 3.785 L, imperial gallon ≈ 4.546 L — about 20 % apart. UK fuel economy figures use imperial gallons; US pump prices use the US gallon. Check the source before comparing.

How many degrees in 1 radian?

1 rad = 180 / π ≈ 57.2958°. Common conversions: π / 2 rad = 90°, π rad = 180°, 2π rad = 360°. Most programming languages default to radians for sin / cos, so graphics code often needs the deg → rad direction.

How many newtons in 1 pound-force?

1 lbf ≈ 4.448 N and 1 N ≈ 0.2248 lbf. Structural load specs, torque ratings, and fastener pre-load values commonly need the N ↔ lbf swap when reading drawings from different markets.

How do I convert Kelvin to Celsius?

Use °C = K − 273.15 and K = °C + 273.15. Absolute zero 0 K = −273.15 °C, the triple point of water 273.16 K ≈ 0.01 °C — the SI zero point.

Related tools

After the conversion, you can keep working with related data and time tools to normalise other fields and cross-check timestamps.