Unit Converter
Last updated: June 5, 2026Length, weight, volume, speed & more.
Unit Converter is a free online calculator to length, weight, volume, speed & more. It runs entirely in your browser, so your files never leave your device — nothing is uploaded. There's no sign-up, no watermark, and it works on any modern browser on desktop or mobile.
How to use Unit Converter
The Unit Converter handles length, weight, volume, area, speed, data and time in one place. Pick a category, choose your 'from' and 'to' units, and convert instantly with accurate factors. Free and runs entirely in your browser.
Read the full guide: Unit Converter: Length, Weight, Volume & More (Free)
- 1Choose a category (length, weight, etc.).
- 2Pick the units to convert from and to.
- 3Enter a value to see the result.
Many categories
Length, weight, volume, area, speed, data and time in one tool.
Accurate
Uses precise conversion factors for metric and imperial units.
Free & private
Runs on your device with no sign-up.
Scaling a recipe to metric
Cooking from a US recipe that lists cups, tablespoons and teaspoons but your kitchen scale and jugs are metric? Switch to the Volume category and convert cups to milliliters, tablespoons to ml or US gallons to liters in seconds. With one cup at about 237 ml and a tablespoon near 14.8 ml, you get accurate amounts so baking ratios stay right and nothing comes out dense or dry.
Checking marine and wind speeds in knots
Sailors, pilots and divers often read speed in knots while everyday apps report mph or km/h. Open the Speed category to convert knots to miles per hour, kilometers per hour or meters per second instantly. One knot equals roughly 1.15 mph or 1.85 km/h, so you can quickly translate a forecast wind speed or boat log reading into the units you actually think in.
Converting file and storage sizes
Comparing a download cap, disk quota or backup size means juggling bytes, KB, MB, GB and TB. The Data category converts between all of them using binary 1024-based steps, the way operating systems count. Turn 5,000 MB into GB, or a 2 TB drive into gigabytes, to sanity-check whether a folder fits, how long a transfer runs, or if you are near a hosting or cloud storage limit.
Unit Converter — frequently asked questions
What units can I convert?
Length (mm–miles), weight (mg–pounds), volume, area, speed, digital storage (B–TB) and time, with both metric and imperial units.
How do I convert km to miles?
Choose Length, set 'from' to kilometers and 'to' to miles, then type the value — 1 km ≈ 0.621 miles.
Is it free?
Yes, completely free.
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