Free online unit converter

Unit Converter

Convert length, weight, temperature, volume and 30+ other quantities instantly. Search for a conversion or browse by category.

categories: 21
conversion pages: 514
calculators: 138

Time tools

Online clock, alarm, timer, world clock, countdowns and calendar tools — nothing to install.

Online Clock

Live clock with 34 themes — pendulum, cuckoo, flip, neon; ticking and full screen.

Alarm Clock

Repeating alarms, your own sound, snooze and keep-screen-awake.

Timer

Countdowns from 10 seconds to 24 hours; full screen, colours, end time.

Stopwatch

Hundredths of a second, laps and CSV download.

Pomodoro Timer

25-minute focus sessions with breaks, notifications and daily stats.

Interval Timer

Tabata, HIIT and EMOM workouts with voice cues and beeps.

World Clock

Live time in 97 cities with time differences and DST dates.

Time Zone Converter

Convert to several zones at once, with a meeting planner.

US Federal Holidays

Observed dates, days until each holiday and long-weekend ideas.

Business Day Calculator

Working days between dates, or add business days to a deadline.

Days Between Dates

Days, weeks and months between two dates, with business days.

Countdown

Days until Christmas, New Year and more — or make your own.

Hijri Date Converter

Islamic to Gregorian dates and back, plus the Ottoman calendar.

Moon Phases

Today's moon phase and the next full moon, with a moon calendar.

Golden Hour

Golden and blue hour times for photos, by city or your location.

Explore calculation tools

Start with a clear task area, then open a focused tool with its units and assumptions visible.

Unit Conversions

Accurate unit conversions and practical unit guides.

21 categories

Everyday Calculators

Home projects, transport, routines and practical planning.

44 available tools

Business Calculators

Break-even, gross margin, markup and advertising-return checks.

59 available tools

Finance Calculators

Mortgage, loan and compound-growth planning estimates.

59 available tools

Automotive Calculators

Tires, fuel use, EV charging and vehicle running-cost planning.

59 available tools

Data & Computing

Number bases, pixels, video bitrate and data-storage tools.

59 available tools

Fitness Calculators

One-rep max and running-pace training estimates.

59 available tools

Decision & Savings

Energy, cost and payback comparisons using your own inputs.

6 available tools

Engineering & STEM

Focused engineering, chemistry and science tools with clear units.

59 available tools

Unit conversions

Each card opens a live category page and surfaces one or two real conversion examples.

All conversions

Length

Mass

Volume

Temperature

Time

Area

Speed

Data Storage

Electricity

Pressure

Energy and power

Density

Force

Flow Rate

Torque

Momentum

Dynamic Viscosity

Shoe Size Converter

Kitchen Measurement Converter

Recipe Converter

Historical Units

More Conversions

More conversion categories

Angle Conversions

Frequency Conversions

Volumetric Flow Rate Conversions

Mass Flow Rate Conversions

Magnetic Field Conversions

Magnetic Flux Conversions

Kinematic Viscosity Conversions

Thermal Conductivity Conversions

View all conversions

Popular conversions

Open frequently used live conversion pages directly from here.

All conversions

Frequently searched units

Read the definition, history and conversions for these units.

Milliampere

Bar

Milligram

Yard

Fahrenheit

Engineering calculators

Current technical tools for pressure, fluids and heat transfer.

Pressure, Force and Area

Hydrostatic Pressure

Heat Energy

Heat Conduction

Reynolds Number

Ohm's Law

Electrical Calculators

Fluids & Piping

Heat Transfer

Dimensionless Numbers

Mechanics & Materials

More Calculators

Geography calculators

Map scale, GPS coordinates, solar time and facts for every country.

Map Scale Calculator

Map distance to ground distance, real area, find the scale and draw a scale bar.

Coordinate Converter

Decimal degrees, DMS, degrees decimal minutes and UTM.

Solar Time Calculator

Local mean time and true solar noon from longitude.

World Map

Clickable political map of 196 countries with capitals, area and time zones.

Countries and Capitals

Every country by continent with its capital, UTC offset and calling code.

All Geography Calculators

Everyday calculators

Practical tools for home projects, routines, transport and personal planning.

View all 44 tools

Home and DIY calculators

19 tools

Health and daily routines

11 tools

India: land, gold, construction, GST and loans

8 tools

School and study

1 tools

Transport, cost and comparison tools

7 tools

Decision & savings calculators

Compare recurring costs and simple payback using your own prices and assumptions.

View all 6 tools

EV vs Gas Running Cost Calculator

Compare annual gasoline and electricity costs with your own prices, consumption figures and optional vehicle price difference.

LED Savings Calculator

Estimate energy, cost savings and simple payback when replacing older bulbs with LEDs.

Remote Work vs Office Cost Calculator

Compare commute, lunch and at-home costs to estimate the annual financial difference of remote work.

Insulation Payback Calculator

Estimate wall heat-loss reduction, annual energy savings and simple insulation payback.

Heat Pump vs Boiler Cost Calculator

Compare annual heating cost and simple payback using local fuel and electricity prices.

Solar Payback Calculator

Estimate solar production, self-consumption value, export value and simple payback.