SMART BOX

Calculate and convert anything

Type a sum, a unit or currency conversion, a percentage or a date question in plain words. You get the answer, how it was understood and the working as you type.

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Things you can type

Units

Currency

Percentages

Dates

Maths

Big numbers

SUPPORTED UNITS

156 units in 14 families

Plus about 160 currencies with daily reference rates. Spelling variants, plurals and symbols all work: metre or meter, ft or feet, °C or celsius.

Length

nanometres (nm), micrometres (µm), millimetres (mm), centimetres (cm), decimetres (dm), metres (m), kilometres (km), thou (mil), inches (in), hands (hand), feet (ft), yards (yd), chains (ch), furlongs (furlong), miles (mi), nautical miles (nmi), astronomical units (au), light years (ly)

Mass

micrograms (µg), milligrams (mg), carats (ct), grams (g), grains (gr), tolas (tola), ounces (oz), troy ounces (oz t), pounds (lb), kilograms (kg), stone (st), quintals (q), tonnes (t), US short tons (US ton), UK long tons (UK ton)

Temperature

degrees Celsius (°C), degrees Fahrenheit (°F), kelvins (K), degrees Rankine (°R)

Volume

millilitres (mL), centilitres (cL), decilitres (dL), litres (L), hectolitres (hL), cubic metres (m³), cubic centimetres (cm³), cubic inches (in³), cubic feet (ft³), cubic yards (yd³), US teaspoons (tsp), US tablespoons (tbsp), US fluid ounces (US fl oz), US cups (cup), metric cups (metric cup), US pints (US pt), US quarts (US qt), US gallons (US gal), UK fluid ounces (UK fl oz), UK cups (UK cup), UK pints (UK pt), UK quarts (UK qt), UK gallons (UK gal), oil barrels (bbl)

Area

square millimetres (mm²), square centimetres (cm²), square metres (m²), ares (a), hectares (ha), square kilometres (km²), square inches (in²), square feet (ft²), square yards (yd²), acres (ac), square miles (mi²), marlas (272.25 sq ft) (marla), marlas (225 sq ft) (marla), kanals (5,445 sq ft) (kanal), kanals (4,500 sq ft) (kanal)

Speed

metres per second (m/s), kilometres per hour (km/h), feet per second (ft/s), miles per hour (mph), knots (kn)

Time

nanoseconds (ns), microseconds (µs), milliseconds (ms), seconds (s), minutes (min), hours (h), days (d), weeks (wk), fortnights (fortnight), months (mo), years (yr), decades (decade), centuries (century)

Data

bits (bit), bytes (B), kilobits (kb), kilobytes (kB), megabits (Mb), megabytes (MB), gigabits (Gb), gigabytes (GB), terabits (Tb), terabytes (TB), petabytes (PB), kibibytes (KiB), mebibytes (MiB), gibibytes (GiB), tebibytes (TiB)

Data rate

bits per second (bit/s), kilobits per second (kbit/s), megabits per second (Mbit/s), gigabits per second (Gbit/s), kilobytes per second (kB/s), megabytes per second (MB/s), gigabytes per second (GB/s), mebibytes per second (MiB/s)

Pressure

pascals (Pa), hectopascals (hPa), kilopascals (kPa), megapascals (MPa), millibars (mbar), bars (bar), atmospheres (atm), pounds per square inch (psi), kilopounds per square inch (ksi), millimetres of mercury (mmHg), inches of mercury (inHg), torr (Torr)

Energy

electronvolts (eV), joules (J), kilojoules (kJ), megajoules (MJ), calories (cal), kilocalories (kcal), watt hours (Wh), kilowatt hours (kWh), megawatt hours (MWh), British thermal units (BTU), foot-pounds (ft·lbf)

Power

watts (W), kilowatts (kW), megawatts (MW), horsepower (hp), metric horsepower (PS), BTU per hour (BTU/h)

Angle

radians (rad), degrees (°), gradians (grad), arcminutes (arcmin), arcseconds (arcsec), turns (turn)

Fuel economy

kilometres per litre (km/L), litres per 100 km (L/100 km), miles per US gallon (mpg (US)), miles per UK gallon (mpg (UK))

UNIT CONVERTERS

Converters for every kind of unit

Number tools

Popular conversions

QUESTIONS

Smart box FAQ

What can I type?

Plain questions with numbers: unit conversions such as “5 ft 7 in to cm”, currency such as “100 usd to pkr”, percentages such as “18% of 2400”, date questions such as “90 days from today”, and maths such as “(3+4)^2/7”. Lakh, crore, million and k are understood, so “1.5 lakh km in miles” works.

How accurate are the unit conversions?

Each unit is built from its legal definition, for example 1 inch = 0.0254 m and 1 pound = 0.45359237 kg exactly. Results show up to seven significant figures and the working lists the factor used. Units with more than one local definition, such as the marla or the gallon, say so and offer the alternatives.

Where do the exchange rates come from?

Mid-market reference rates from Exchange Rate API, refreshed once a day on our server. Each answer shows the date of the rates. Banks, cards and money changers add a margin, so the amount you receive will be lower.

What if a unit could mean two things?

The box picks the most common reading and offers the others as buttons. For example “oz” is a weight ounce unless you convert it to a volume, “gallon” is a US gallon with the UK gallon one tap away, and “Rs” follows your region.

Is my question sent anywhere?

No. Questions are answered in your browser. The only request the page makes is for the daily exchange-rate table, from this site, and only when you ask about money.

How do dates handle month ends?

Adding months keeps the day of the month where it can. When that day does not exist, such as 31 January plus one month, the result moves back to the last day of the month and the working says so.