US Unit Conversion Calculator

Convert seamlessly between US Customary and Metric (SI) units across 11 primary measurement domains: Length, Weight, Temperature, Fluid Volume, Area, Speed, Digital Data, Time, Energy, Pressure, and Fuel Economy.

Universal Unit Converter

⚡ Quick Presets:

Educational Purpose Only: This utility is provided for educational, academic, and general calculation purposes only. While conversions follow standard international unit definitions, mission-critical engineering, aviation, or medical applications should rely on certified laboratory tools.

Data Notice: Standard conversion factors follow NIST (National Institute of Standards and Technology) and Bureau International des Poids et Mesures (BIPM) definitions. Verify critical measurements against official regulatory standards.

Common US Customary to Metric Conversion Tables

Use these cheat sheets for quick everyday unit conversion lookup across common US standards.

1. Length & Distance Conversion Table

US Customary Unit Metric Equivalent Exact Formula
1 Inch (in) 2.54 Centimeters (cm) 1 in = 2.54 cm
1 Foot (ft) 0.3048 Meters (m) 1 ft = 12 in = 0.3048 m
1 Yard (yd) 0.9144 Meters (m) 1 yd = 3 ft = 0.9144 m
1 Mile (mi) 1.60934 Kilometers (km) 1 mi = 5,280 ft = 1.60934 km

2. Weight & Mass Conversion Table

US Customary Unit Metric Equivalent Exact Formula
1 Ounce (oz) 28.3495 Grams (g) 1 oz = 28.3495 g
1 Pound (lb) 0.453592 Kilograms (kg) 1 lb = 16 oz = 0.453592 kg
1 US Short Ton (ton) 907.185 Kilograms (kg) 1 ton = 2,000 lbs = 907.185 kg
1 Metric Ton (t) 2,204.62 Pounds (lbs) 1 t = 1,000 kg = 2,204.62 lbs

3. Key Temperature Benchmarks (°F vs °C)

Benchmark / Standard Fahrenheit (°F) Celsius (°C) Kelvin (K)
Absolute Zero -459.67 °F -273.15 °C 0 K
Water Freezing Point 32 °F 0 °C 273.15 K
Room Temperature 68 °F – 72 °F 20 °C – 22.2 °C 293.15 K
Human Body Temperature 98.6 °F 37 °C 310.15 K
Water Boiling Point (Sea level) 212 °F 100 °C 373.15 K

Understanding Unit Conversions: US Customary vs. Metric System

The United States primarily utilizes the US Customary System for everyday measurements, commercial trade, construction, and highway signage (miles, feet, pounds, Fahrenheit, and US gallons). Conversely, the majority of global trade, scientific research, international logistics, and medicine rely on the International System of Units (SI Metric System).

How Temperature Conversions Work

Unlike length or mass, temperature scales do not share a zero starting point. Water freezes at 32°F on the Fahrenheit scale, but 0°C on the Celsius scale:

  • Fahrenheit to Celsius: Subtract 32 from the Fahrenheit temperature, then multiply by 5/9: °C = (°F − 32) × 5/9
  • Celsius to Fahrenheit: Multiply the Celsius temperature by 9/5 (or 1.8), then add 32: °F = (°C × 9/5) + 32
  • Celsius to Kelvin: Add 273.15: K = °C + 273.15

Frequently Asked Questions (FAQs)

What is the difference between a US Gallon and a UK Imperial Gallon?
A US liquid gallon is equal to 3.78541 Liters (128 US fl oz), whereas a UK Imperial gallon is larger, equaling 4.54609 Liters (160 UK fl oz). This calculator defaults to the standard US Liquid Gallon.
How do I convert pounds (lbs) to kilograms (kg) mentally?
A quick mental estimate is to divide the weight in pounds by 2, then subtract 10% from that result. For example, 200 lbs ÷ 2 = 100; 100 − 10 = 90 kg (exact value is 90.718 kg).
Is a nautical mile the same as a statute mile?
No. A standard US statute mile is 5,280 feet (1,609.34 meters), whereas a nautical mile is based on one minute of arc along the Earth's meridian, equaling 6,076.12 feet (1,852 meters).
Why does 1 Acre equal 43,560 square feet?
Historically in English customary law, an acre was defined as the area of land a yoke of oxen could plow in one day: specifically one furlong (660 feet) in length by one chain (66 feet) in width, resulting in exactly 43,560 square feet.
What is the difference between binary storage (GiB) and decimal storage (GB)?
In traditional computing, 1 Kilobyte equals 1,024 Bytes ($2^{10}$). Hard drive manufacturers often use decimal multiples where 1 KB equals 1,000 Bytes ($10^3$). This converter follows standard binary computing architecture ($1,024$ multiplier).
How do you convert US MPG to Liters per 100 km (L/100km)?
Because Miles per Gallon is a distance-per-volume ratio and L/100km is a volume-per-distance ratio, their relationship is inverse: L/100km = 235.215 ÷ US MPG.