Unit Converter
Convert metric, imperial, and US units across 13 categories: length, area, volume, weight, time, temperature, speed, pressure, energy, power, data storage, angle, and frequency.
Thousands grouping
Common only
International System (SI)
Millimeter
mm
Centimeter
cm
Meter
m
Kilometer
km
US Customary (US)
Inch
in
Foot
ft
Yard
yd
Mile
mi
Length Conversion
Meters as base; imperial factors: 1 in = 2.54 cm; 1 ft = 0.3048 m
Common
• 1 kilometer (km) = 1000 meters (m)
• 1 meter (m) = 100 centimeters (cm)
• 1 centimeter (cm) = 10 millimeters (mm)
• 1 inch (in) = 2.54 centimeters (cm)
• 1 foot (ft) = 0.3048 meters (m)
• 1 nautical mile (nmi) = 1852 meters (m)
More
• 1 millimeter (mm) = 1000 micrometers (µm)
• 1 micrometer (µm) = 1000 nanometers (nm)
• 1 yard (yd) = 0.9144 meters (m)
• 1 mile (mi) = 1.609344 kilometers (km)
• 1 foot (ft) = 0.3048 meters (m)
Thousands grouping
Common only
International System (SI)
Square Meter
m²
Square Kilometer
km²
Land
Hectare
ha
Acre
ac
Imperial
Square Inch
in²
Square Foot
ft²
Area Conversion
Area equals squared length; acre differs greatly from m²
Common
• 1 square kilometer (km²) = 1,000,000 square meters (m²)
• 1 square meter (m²) = 10,000 square centimeters (cm²)
• 1 hectare (ha) = 10,000 square meters (m²)
• 1 acre (acre) = 4046.8564224 square meters (m²)
More
• 1 are (a) = 100 square meters (m²)
• 1 square kilometer (km²) = 100 hectares (ha)
• 1 square mile (mi²) ≈ 2.589988 square kilometers (km²)
• 1 square foot (ft²) ≈ 0.092903 square meters (m²)
• 1 square inch (in²) = 6.4516 square centimeters (cm²)
Thousands grouping
Common only
International System (SI)
Milliliter
ml
Liter
L
Cubic Meter
m³
US Customary (US)
Cup (US)
cup
Quart (US)
qt
Gallon (US)
gal
Volume Conversion
Liters as common base; here ‘gallon’ denotes the US gallon
Common
• 1 cubic meter (m³) = 1000 liters (L)
• 1 liter (L) = 1000 milliliters (mL)
• 1 gallon (US gal) = 4 quarts (US qt)
• 1 quart (US qt) = 2 pints (US pt)
• 1 gallon (US gal) ≈ 3.78541 liters (L)
• By default, this tool uses US customary (US) for common volume units; Imperial values differ.
More
• 1 pint (US pt) = 2 cups (US cup)
• 1 cup (US cup) = 8 fluid ounces (US fl oz)
• 1 fluid ounce (US fl oz) ≈ 29.5735 milliliters (mL)
• 1 tablespoon (tbsp) ≈ 14.7868 milliliters (mL)
Thousands grouping
Common only
International System (SI)
Milligram
mg
Gram
g
Kilogram
kg
Metric Ton
t
Avoirdupois
Ounce
oz
Pound
lb
Weight Conversion
Kilograms as base; don't confuse mass (kg) with force (N)
Common
• 1 metric ton (t) = 1000 kilograms (kg)
• 1 kilogram (kg) = 1000 grams (g)
• 1 gram (g) = 1000 milligrams (mg)
• 1 stone (st) = 14 pounds (lb)
• 1 pound (lb) = 16 ounces (oz)
• 1 pound (lb) = 0.45359237 kilograms (kg)
• 1 ounce (oz) = 28.349523125 grams (g)
More
• 1 short ton (US ton) = 2000 pounds (lb) ≈ 907.18474 kilograms (kg)
• 1 long ton (imperial ton) = 2240 pounds (lb) ≈ 1016.04691 kilograms (kg)
• 1 carat (ct) = 0.2 grams (g)
• 1 grain (gr) ≈ 64.79891 milligrams (mg)
• Note: ounce (oz) differs between avoirdupois and troy systems
Thousands grouping
Common only
Standard
Second
s
Minute
min
Hour
h
Extended
Day
d
Week
wk
Time Conversion
Seconds as base; month/year use average lengths, not exact calendar months or leap years
Common
• 1 week (wk) = 7 days (d)
• 1 day (d) = 24 hours (h)
• 1 hour (h) = 60 minutes (min)
• 1 minute (min) = 60 seconds (s)
• 1 second (s) = 1000 milliseconds (ms)
• 1 millisecond (ms) = 1000 microseconds (µs)
More
• 1 nanosecond (ns) = 10^-9 seconds (s)
• 1 picosecond (ps) = 10^-12 seconds (s)
Thousands grouping
Common only
Primary
Celsius
°C
Fahrenheit
°F
Kelvin
K
Temperature Conversion
Non-linear (C ↔ F involves scaling+offset); negatives supported
Common
• Fahrenheit (°F) = Celsius (°C) × 9/5 + 32
• Kelvin (K) = Celsius (°C) + 273.15
• Example: −40 degrees Celsius (°C) = −40 degrees Fahrenheit (°F)
More
• Celsius (°C) = (Fahrenheit (°F) − 32) × 5/9
• Celsius (°C) = Kelvin (K) − 273.15
• Rankine (°R) = Fahrenheit (°F) + 459.67
Thousands grouping
Common only
International System (SI)
Meter per Second
m/s
Kilometer per Hour
km/h
US Customary (US)
Mile per Hour
mph
Nautical
Knot
kn
Speed Conversion
Common: m/s, km/h, mph; knots (kn) convert via m/s
Common
• 1 meter per second (m/s) = 3.6 kilometers per hour (km/h)
• 1 kilometer per hour (km/h) ≈ 0.27778 meters per second (m/s)
• 1 mile per hour (mph) = 1.609344 kilometers per hour (km/h)
• 1 knot (kn) = 1852 meters per hour (m/h) ≈ 0.514444 meters per second (m/s)
More
• 1 centimeter per second (cm/s) = 0.01 meters per second (m/s)
• 1 foot per second (ft/s) ≈ 0.3048 meters per second (m/s)
• 1 kilometer per minute (km/min) = 1000 meters per minute (m/min)
• 1 meter per minute (m/min) ≈ 0.0166667 meters per second (m/s)
Thousands grouping
Common only
International System (SI)
Kilopascal
kPa
Engineering
Bar
bar
Medical
Millimeter of Mercury
mmHg
Standard
Standard Atmosphere
atm
US Customary (US)
Pound per Square Inch
psi
Pressure Conversion
Pascals as base; gauge/absolute not covered
Common
• 1 bar (bar) = 100,000 pascals (Pa)
• 1 standard atmosphere (atm) ≈ 101,325 pascals (Pa)
• 1 pound per square inch (psi) ≈ 6894.757 pascals (Pa)
• 1 Torr (Torr) = 1/760 atm ≈ 133.322 pascals (Pa)
• 1 millimeter of mercury (mmHg) ≈ 133.322 pascals (Pa) (approx. at standard conditions)
• 1 kilopascal (kPa) = 1000 pascals (Pa)
More
• 1 millibar (mbar) = 100 pascals (Pa)
• 1 inch of mercury (inHg) ≈ 3386.389 pascals (Pa)
• 1 kilogram-force per square centimeter (kgf/cm²) ≈ 98,066.5 pascals (Pa)
Thousands grouping
Common only
International System (SI)
Joule
J
Kilojoule
kJ
Electric
Kilowatt Hour
kWh
Thermal
Kilocalorie
kcal
Energy Conversion
J, cal, kWh common; dietary calories usually mean kcal
Common
• 1 kilowatt-hour (kWh) = 3.6×10^6 joules (J)
• 1 calorie (cal) ≈ 4.184 joules (J)
• 1 kilocalorie (kcal) = 1000 calories (cal)
• 1 electronvolt (eV) ≈ 1.602176634×10^-19 joules (J)
More
• 1 kilojoule (kJ) = 1000 joules (J)
• 1 British thermal unit (BTU, ISO) ≈ 1055.056 joules (J) (varies)
Thousands grouping
Common only
International System (SI)
Watt
W
Kilowatt
kW
Horsepower
Horsepower (Mechanical)
hp
Metric Horsepower
PS
Power Conversion
W, kW, hp (mechanical), PS (metric), bhp (brake)
Common
• 1 megawatt (MW) = 1000 kilowatts (kW)
• 1 kilowatt (kW) = 1000 watts (W)
• 1 horsepower (hp) ≈ 745.7 watts (W)
• 1 metric horsepower (PS) ≈ 735.5 watts (W)
• 1 brake horsepower (bhp) ≈ 745.7 watts (W)
More
• 1 kilowatt (kW) ≈ 1.34102 horsepower (hp)
• 1 metric horsepower (PS) ≈ 0.7355 kilowatts (kW)
Thousands grouping
Common only
Decimal
Kilobyte
KB
Megabyte
MB
Gigabyte
GB
Terabyte
TB
Data Size Conversion
Decimal vs binary conventions; choose per vendor/system
Common
• Decimal: 1 kilobyte (KB) = 1000 bytes (B); 1 megabyte (MB) = 1000 kilobytes (KB); 1 gigabyte (GB) = 1000 megabytes (MB)
• Binary: 1 kibibyte (KiB) = 1024 bytes (B); 1 mebibyte (MiB) = 1024 kibibytes (KiB); 1 gibibyte (GiB) = 1024 mebibytes (MiB)
• Approx: 1 megabyte (MB) ≈ 0.9537 mebibyte (MiB); 1 gibibyte (GiB) ≈ 1.0737 gigabytes (GB)
More
• 1 terabyte (TB) = 1000 gigabytes (GB); 1 tebibyte (TiB) = 1024 gibibytes (GiB)
• Binary prefixes (KiB/MiB/GiB) denote binary units; avoid mixing with KB/MB/GB
Thousands grouping
Common only
Degree
Degree
°
Radian
Radian
rad
Revolution
rev
Angle Conversion
Degrees ↔ radians; programming/math often use radians
Common
• 1 degree (°) = π/180 radians (rad)
• 1 radian (rad) ≈ 57.2957795 degrees (°)
• 1 turn (rev) = 360 degrees (°)
More
• 1 grad (grad) = 0.9 degrees (°)
Thousands grouping
Common only
Primary
Hertz
Hz
Kilohertz
kHz
Megahertz
MHz
Gigahertz
GHz
Frequency Conversion
Hz as base; kHz/MHz/GHz are decimal multiples
Common
• 1 kilohertz (kHz) = 1000 hertz (Hz)
• 1 megahertz (MHz) = 1000 kilohertz (kHz)
• 1 gigahertz (GHz) = 1000 megahertz (MHz)
More
• 1 hertz (Hz) = 1/second (s) (period)
• 1 hertz (Hz) = 60 revolutions per minute (RPM)
Quick Start
Common Scenarios
Travel/maps
km ↔ mi, ft ↔ m for route planning and international comparison
Home/DIY
mm/cm ↔ inch/ft for orders and labels
Shipping/fees
kg ↔ lb/oz for parcels and cross‑border logistics
Cooking recipes
g ↔ oz, mL ↔ cup for local measuring tools
Weather & perception
°C ↔°F across regions
Oven/lab setpoints
°C ↔°F ↔ K for precise control
Real estate/land
m² ↔ ft² and hectare/acre ↔ m² for listings and surveys
Liquids/mixing
mL/L ↔ fl oz/gal for drinks/chemistry
Schedules/durations
min/h ↔ s, week ↔ day for rosters
Speed/pacing
km/h ↔ mph, m/s ↔ km/h for vehicles/running
Tire/pipe pressure
bar ↔ psi ↔ kPa to match manuals
Energy/billing
kWh ↔ J (power × time rough estimate)
Motors/engines
kW ↔ hp/PS for nameplates/regulations
Storage/bandwidth
MB/GB ↔ MiB/GiB, bit ↔ Byte per vendor/system
Angle/radian
°↔ rad for CAD/math
Audio/electronics
Hz ↔ kHz/MHz, RPM ↔ Hz
Conversion Parameters & Precision
Unit Systems & Boundaries
Usage Advice
Common Formulas
URL Quick Fill
Limitations & Compatibility
Privacy & Security
FAQ
Very large and very small values are shown in e-notation to keep results readable and avoid long strings of zeros. The numeric value is unchanged; only the display format switches.
Yes. We strip thousands separators and treat it as 1234.56
For readability, we show dynamic significant digits and trim meaningless trailing zeros; extreme values use e-notation
KB is decimal, so 1 KB = 1000 bytes. KiB is binary, so 1 KiB = 1024 bytes. Storage vendors often use decimal units, while operating systems and developer tools may use binary units.