Unit Converters

Length, mass, temperature, area, volume, speed, angles, capacitance, and density with defined factors.

Convert physical units using exact definitions: length, weight and mass, temperature, area, volume, speed, angles, capacitance, coordinates, and density — including US liquid versus Imperial gallons and statute versus nautical miles. Computing units live under Technology.

105 free tools · each with formula, worked example & methodology notes

Category context

The discipline of unit conversion

A conversion must name both the source and destination definitions. Regional gallons, miles, temperature scales, and data prefixes can look similar while representing different quantities.

Method and background

Standardized units make measurements comparable across countries and disciplines. The reliable pattern is a defined factor or relationship followed by clear labeling and sensible rounding.

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Calculator directory

Choose the tool that matches your question

105 tools arranged by purpose, so you can scan the right group before opening a calculator.

33 tools

Length, area, and volume

Convert distance, surface area, volume, and everyday size measurements.

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Length Converter

Convert metric and international customary lengths, including statute and nautical miles, using defined factors.

You enter: Length · From unit · To unit

Example: 1.609344 km

Open Length Converter →

Area Converter

Convert square metric and customary units, hectares, and international acres without confusing linear and area factors.

You enter: Area · From unit · To unit

Example: 4046.8564224 m2

Open Area Converter →

Volume Converter

Convert liters, milliliters, cubic units, US liquid gallons, and Imperial gallons with explicit gallon definitions.

You enter: Volume · From unit · To unit

Example: 3.785411784 l

Open Volume Converter →

Speed Converter

Convert meters per second, kilometers per hour, miles per hour, feet per second, and knots.

You enter: Speed · From unit · To unit

Example: 96.56064 km/h

Open Speed Converter →

Drawing Scale Converter

Convert a drawing length to a real length or reverse it using a clear 1-to-N scale denominator.

You enter: Entered length · Scale denominator · Conversion direction

Example: 5 drawing units at 1:100 represents 500 real units.

Open Drawing Scale Converter →

Acres to Square Feet Converter

Convert international acres into square feet, square metres, hectares, and square yards with the unit basis stated.

You enter: International acres

Example: 1 international acre = 43,560 square feet, 4,046.8564224 square metres, 0.40468564224 hectares, and 4,840 square yards.

Open Acres to Square Feet Converter →

Drops to Milliliters Converter

Convert a counted number of drops to milliliters, liters, and microliters using the measured drop volume for the actual dispenser.

You enter: Number of drops · Milliliters per drop

Example: Twenty drops at 0.05 mL per drop equal 1 mL, 0.001 L, and 1,000 µL; the implied rate is 20,000 drops per liter.

Open Drops to Milliliters Converter →

18 tools

Mass, density, and temperature

Compare mass, weight, density, and temperature definitions across systems.

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mmol/L to mg/dL Calculator

Convert a selected laboratory analyte from mmol/L to mg/dL using its molecular weight, with a reverse-conversion check shown beside the answer.

You enter: Analyte · Concentration

Example: Glucose 5.5 mmol/L × 180.156 ÷ 10 = 99.0858 mg/dL.

Open mmol/L to mg/dL Calculator →

17 tools

Energy, power, and force

Convert energy, power, pressure, force, torque, and related mechanical units.

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Torque Unit Converter

Convert newton-meters, kilonewton-meters, pound-feet, pound-inches, kilogram-force meters, and kilogram-force centimeters.

You enter: Torque · From unit · To unit

Example: 100 lbf ft = 135.581794833 N m.

Open Torque Unit Converter →

3 tools

Electricity and frequency

Capacitance, frequency, voltage, current, and electrical engineering unit changes.

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5 tools

Angles and coordinates

Degrees, radians, decimal degrees, DMS, and coordinate representations.

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7 tools

Currency and everyday sizes

Custom-rate currency scenarios, shoe sizes, and familiar regional comparisons.

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Shoe Size Conversion

Convert an approximate shoe size among US men's, US women's, UK, EU, and Japanese length systems.

You enter: Known shoe size · Known sizing system

Example: The calculator estimates a foot length and corresponding UK, EU, US women, and Japanese sizes.

Open Shoe Size Conversion →

22 tools

More Unit Converters tools

Additional tools in this category that do not yet need a narrower navigation label.

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SCFM to SI Flow Converter

Convert standard cubic feet per minute into cubic metres per second, cubic metres per hour, and litres per second.

You enter: Standard cubic feet per minute

Example: 100 scfm = 0.04719474432 m³/s, 169.901079552 m³/h, and 47.19474432 L/s.

Open SCFM to SI Flow Converter →

Decimal to Octal Converter

Convert a safe-range decimal integer to prefixed octal and binary notation while preserving negative values and showing the digit count.

You enter: Decimal integer

Example: 214 in base 10 is 0o326 in base 8 and 11010110 in base 2; the octal magnitude has three digits.

Open Decimal to Octal Converter →

Days to Months Duration Converter

Convert elapsed days to months and years using an average Gregorian, 30-day billing, or 365-day-year convention.

You enter: Elapsed days · Month convention

Example: 90 elapsed days are about 2.956 months and 0.2463 years under the average Gregorian-month convention; a 30-day billing convention gives exactly 3 months.

Open Days to Months Duration Converter →

Numbers to Words Converter

Convert whole numbers from zero through 999,999,999 into canonical English words, or parse those words back into a decimal integer.

You enter: Conversion direction · Value to convert

Example: The decimal integer 2026 becomes two thousand twenty-six; parsing those words returns 2026.

Open Numbers to Words Converter →

Calculator usage statistics

Most-used Unit Converters tools

This section counts anonymous successful Calculate submissions, not unique visitors. Counts and top tools appear only when trusted aggregate data is available; country analysis is shown only under the same condition and reporting threshold.

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How to use these tools

Each calculator shows its formula, assumptions, and a worked example. Enter your values, choose Calculate, and copy results for reports or planning. Financial and health tools are planning estimates with stated limits, not professional advice.

Frequently asked questions

Which gallon, mile, and gigabyte are used?

US liquid gallons and Imperial gallons are separate options. Miles default to statute miles with nautical miles available. GB means 10^9 bytes while GiB means 2^30 bytes.

Are currency rates provided?

No. Converters cover physical units and data storage only. No live or historical currency, tax, or location data is implied.