How do you convert units in plain English?
Type a number, a unit and what you want it in, the way you would say it: 5c in f gives 41 °F. Leave out the target to get the most readable unit, or write a sum: 256mb * 50k is 12.8 TB.
The calculator reads as you type and suggests units as you start writing them. Pick one with the arrow keys and Tab, or click any of the other readings under the answer to switch to it. The address bar keeps your question, so a link to the page shows the same answer.
Popular questions
What you can type
| Convert | 5c in f · 10 km to miles · 2 gallons as liters |
|---|---|
| Ask | what's 3mb * 5 · how many seconds in a day · 5 kg is how many pounds |
| Maths | 256mb * 50k · (1 + 2) * 3 · 2^10 bytes · 20% of 3 hours · sqrt(16 m^2) · sin(30) (degrees unless you write rad) · asin(0.5) |
| Units together | 100 km / 2 h · 10 GB / 100 Mbps in minutes · 72 kg / (1.8 m)^2 |
| Words | five seconds · two and a half hours · a mile in feet · times, plus, divided by, per |
| Mixed units | 5'11" in cm · 1h 30min in minutes · 5000 s in h min s · 180 cm in ft and in |
| Downloads | 5tb over 100mbs · how long to download 50 GB at 300 meg · 5 GB in 10 minutes · 100 Mbps for 2 hours |
| Dates | days until christmas · working days until 20 dec · 3 weeks from now · 90 days ago · days since 2020-03-11 · what day is 24 dec · week number |
| Clock times | 9:30 + 2h 45min · 9am to 5pm · hours until midnight · half past 3 pm |
| Age | how old am I if born 1990-05-01 · since 1990 · is 2028 a leap year · days in february 2028 |
| Percent | 80 + 20% · 15% off 80 · 20 is what percent of 80 · tip 18% on $45 · percent change from 80 to 100 · 20% of what is 5 |
| Fractions | 1/2 cup in tbsp · 1 1/2 hours in minutes · ¾ cup in ml |
| Time zones | 5pm in tokyo · now in new york · 9am pst to cet · 17:00 london in sydney |
| Kitchen | 1 cup flour in grams · 200 g of sugar in cups · 2 tbsp butter |
| Travel and power | 30 mpg in l/100km · 100 km at 50 km/h · 60 mph in min/mi · 100 W for 8 h at 0.25 eur/kWh · 100 rpm in rad/s |
| Running pace | 5 km in 25 min pace · 10 miles in 1:30 pace · 12 km/h pace · 10 km at 5 min/km |
| Temperature differences | 10 °C warmer than 20 °C · a rise of 5 °C in °F (a difference, so 9 °F, not 41 °F) |
| Screens | 27 inch 4k ppi · 1920x1080 in megapixels · 16:9 at 1200 wide · 3000x2000 at 300 dpi · 60 fps in ms · 144 hz frame time · 12 pt in px · 16 px in rem · 10 in at 300 dpi |
| Numbers | 255 in hex · 0xff in binary · 1e9 in words · 2026 in roman · unix time · 1700000000 in date · 2026-10-25 in unix |
| Money | $20 * 3 · 100 usd in sek (asks for today’s ECB rates first) |
| Names | rate = 100 mbps, then 5 tb / rate · ans * 2 uses the last answer · a = 3; b = 4; sqrt(a^2 + b^2) |
| Short or long | 5s, 5 sec, 5 seconds and 5second are the same; so are km/h, kph and kilometres per hour |
How long will a download take?
Type the size and the speed: 5tb over 100mbs gives 4 days 15 h 7 min. Speeds after “at”, “over” or “on” are read the way providers sell them, so 100mbs and 100 meg are megabits per second; write 100 MB/s for megabytes. Real downloads rarely reach the full line speed, so the answer also shows the time at 90%. Turn it round with 5 GB in 10 minutes for the speed you would need.
Bytes and bits
A byte is 8 bits. File sizes are in bytes (MB, GB) and connection speeds in bits per second (Mbps), so a 100 Mbps line moves at most 12.5 MB a second. kB, MB and GB are powers of 1,000; KiB, MiB and GiB are powers of 1,024, which is what Windows calls “GB”. A size on its own, like 5 MB, is shown in the other one.
Questions
Write it the way you would say it: a number, a unit, and optionally “in” or “to” and the unit you want. 5c in f, 5 kilometres to miles and how many seconds in a day all work. Leave out the target and the calculator picks a readable unit and lists the others.
Yes. Add, subtract, multiply and divide quantities, use brackets, powers (^ or squared) and percentages. Units follow the maths: 100 km / 2 h is a speed, 3 m * 4 m an area and 10 GB / 100 Mbps a time.
Lower-case mb, kb and gb are read as bytes, the way file sizes are written. Mb, Mbit and Mbps are bits. When the reading was a guess, the answer says so and offers the other one in one click.
No. It is a small grammar that runs in your browser. It reads numbers in digits or words, over 200 units with their plurals and abbreviations, dates and time zones, and fixes small typos by matching the nearest unit name. Your question is never sent anywhere. The one exception is currency: only when you ask, the page fetches the European Central Bank’s exchange rates.
From the European Central Bank, through the free Frankfurter service. The page only fetches them after you press “Get today’s rates”, then once a day. The request asks for the rate table only; your question stays in your browser. The ECB publishes once each working day, so the rates are not live.
Length, weight, time, temperature, data size and data rate, area, volume (US and imperial), speed, fuel economy, energy, power, pressure, frequency, force, angle, pixels and 30 currencies, plus words like thousand, million, dozen and percent. Cups and grams convert through about 40 common baking ingredients.