Real-estate agents count in mu, cars drink by the liter, drives shrink after purchase — unit traps hide everywhere in daily life. Here are the ones worth memorizing.
Area: How Land Is Measured
| Unit | Conversion | Mental picture |
|---|---|---|
| 1 mu | ≈ 666.7 m² | about 1.5 basketball courts |
| 1 hectare | = 15 mu = 10,000 m² | a standard football pitch |
| 1 km² | = 100 ha = 1,500 mu | a large residential compound |
Volume and Speed: Gas Stations and Highways
- 1 liter ≈ 0.264 US gallons — renting a car in the US, multiply gallons by 3.785.
- Speed: 1 mph ≈ 1.609 km/h. Colloquially, 'one-twenty' means 120 km/h but 'one hundred mai' actually means 160 km/h — over the limit.
- Maritime and aviation use knots: 1 knot = 1.852 km/h.
Storage: Why 1TB Shows as 931GB
Operating systems count in binary (1GB = 1024MB) while drive makers count in decimal (1GB = one billion bytes). The ~7% gap explains the 'missing' space on every drive, USB stick and memory card — it's a unit convention, not a defect.
Recommended Tools
Area Converter
Convert between square meters, mu, hectares, square kilometers and square feet.
Volume Converter
Convert milliliters, liters, cubic meters, US gallons and fluid ounces.
Data Size Converter
Convert bits, bytes, KB, MB, GB and TB (binary 1024-based).
Speed Converter
Convert m/s, km/h, mph, knots and ft/s in one place.
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FAQ
Does '100 square meters' include shared areas?
Gross floor area includes shared spaces; usable area is what you actually walk on — typically 15-25% smaller. Always confirm which figure is quoted when comparing prices.
Why are US customary units so messy?
They evolved separately from the metric system with awkward ratios (1 quart = 0.946 L). Memorize conversions for the items you buy regularly rather than recalculating each time.