- Which units does this tool cover?
- Length: km↔mi, m↔ft, cm↔in, mm↔in. Weight: kg↔lb, g↔oz, metric tons↔US short tons. Volume: L↔US gallons, mL↔US fluid ounces, L↔US quarts, L↔US pints, L↔US cups. Area: m²↔ft², km²↔mi², hectares↔acres. Temperature: °C↔°F. That's the set people actually use day to day — recipes, road signs, body weight, thermostat, lawn size, gas tank.
- US gallons or UK gallons?
- US. The US gallon is 3.785411784 L; the UK (imperial) gallon is 4.54609 L. They are about 20% different — using the wrong one wrecks recipes and fuel-economy math. This tool uses US gallons, US fluid ounces (29.57 mL), US quarts, US pints, and US cups (236.59 mL) because the majority of imperial-using audiences are in the US. If you need UK gallons, multiply the result by 1.20095 — or use a dedicated UK gallon converter.
- Why does the metric ton convert to a 'short ton' instead of a 'long ton'?
- Same reason — US convention. A US (short) ton is 2,000 lb (907.18474 kg). A UK (long) ton is 2,240 lb (1,016.05 kg). A metric ton is 1,000 kg, which is closer to a long ton than a short ton. In the US, when someone says 'ton' without qualification, they mean short ton. That's what this tool uses.
- How accurate are the conversions?
- Exact where an exact ratio exists by definition (1 inch = 25.4 mm, 1 lb = 0.45359237 kg, 1 US gallon = 3.785411784 L — all of these are defined exactly by international agreement). For other ratios (square miles, acres, short tons) the underlying constants are NIST-published to 7+ significant figures. The tool displays results to 6 significant figures by default, which is more precision than any real-world use needs.
- Does temperature convert correctly for negative numbers?
- Yes. The Celsius-to-Fahrenheit formula is °F = °C × 9/5 + 32, and it works in both directions across the full range. The famous point where both scales agree is −40 (−40 °C = −40 °F). Try it — type −40 in either box and watch the other show −40 too.
- Why is there no Calculate button?
- Because conversion is instant in JavaScript — the math is one multiplication. Forcing you to click a button after typing every value would be theater. Type into either side, the other side updates as you go. That's the whole tool.
- Can I convert from imperial to metric, or only metric to imperial?
- Both. The tool's name says 'Metric to Imperial' because that's the more common search phrase, but the conversion runs in either direction. The two fields are bidirectional — type in the metric field and the imperial updates, type in the imperial field and the metric updates. If you want the imperial value on the left for habit reasons, hit the ↔ swap button to flip them.
- Is anything sent to a server?
- No. Conversion runs entirely in your browser using JavaScript. Nothing is uploaded, logged, or stored. Close the tab and the values are gone.
