Unit Converter
Convert between metric and imperial units instantly. Length, weight, temperature, volume, area, and more.
All Conversions
Quick Reference: Common Conversions
Length
- 1 inch= 2.54 cm
- 1 foot= 30.48 cm
- 1 mile= 1.609 km
- 1 meter= 3.281 feet
Weight
- 1 pound= 0.454 kg
- 1 kilogram= 2.205 lbs
- 1 ounce= 28.35 grams
- 1 stone= 6.35 kg
Volume
- 1 gallon (US)= 3.785 liters
- 1 liter= 0.264 gallons
- 1 cup (AU)= 250 mL
- 1 tablespoon= 20 mL (AU)
Temperature
- 0°C= 32°F (freezing)
- 20°C= 68°F (room temp)
- 37°C= 98.6°F (body temp)
- 100°C= 212°F (boiling)
Australian Measurement Notes
Cooking Measurements
- • AU tablespoon = 20 mL (US = 15 mL)
- • AU cup = 250 mL
- • AU teaspoon = 5 mL
Metric System
- • Australia uses metric for all official purposes
- • Speed limits in km/h
- • Fuel sold by the liter
Why Unit Conversion Matters
Unit conversion is an essential skill in our globally connected world. Whether you're following an American recipe, travelling overseas, shopping online from international retailers, or working in science and engineering, understanding how to convert between different measurement systems is crucial for accuracy and avoiding costly mistakes.
Everyday Applications
- • Converting recipes from US cups to metric measurements
- • Understanding overseas weather forecasts in Fahrenheit
- • Calculating fuel efficiency when comparing cars (L/100km vs MPG)
- • Checking product dimensions on international websites
- • Converting your height and weight for travel documents
Professional Uses
- • Engineering and construction specifications
- • Scientific research and data analysis
- • International trade and shipping
- • Healthcare dosage calculations
- • Real estate property measurements
Metric vs Imperial: A Brief History
The metric system (also known as SI - International System of Units) was developed during the French Revolution in the 1790s to create a unified, decimal-based measurement system. Australia officially adopted the metric system in 1970, completing the transition by 1988.
| Aspect | Metric System | Imperial System |
|---|---|---|
| Base | Decimal (base 10) | Various fractions (12 inches = 1 foot) |
| Countries Using | 195+ countries including Australia | USA, Liberia, Myanmar |
| Length Units | mm, cm, m, km | inch, foot, yard, mile |
| Weight Units | g, kg, tonne | oz, lb, stone, ton |
| Temperature | Celsius (0° = freezing, 100° = boiling) | Fahrenheit (32° = freezing, 212° = boiling) |
Did You Know?
In 1999, NASA's Mars Climate Orbiter was lost because one engineering team used metric units while another used imperial units. The $125 million spacecraft burned up in Mars' atmosphere due to this conversion error. Always double-check your unit conversions!
Quick Mental Conversion Tips
Length Approximations
- • Inches to cm: Multiply by 2.5 (rough estimate)
- • Feet to metres: Divide by 3 (1 ft ≈ 0.3 m)
- • Miles to km: Multiply by 1.6 (or add 60%)
- • Km to miles: Multiply by 0.6 (or subtract 40%)
Weight Approximations
- • Pounds to kg: Divide by 2.2 (or halve and subtract 10%)
- • Kg to pounds: Multiply by 2.2 (or double and add 10%)
- • Ounces to grams: Multiply by 28
- • Stone to kg: Multiply by 6.35
Temperature Formula
- • °C to °F: Multiply by 1.8 (or 9/5), then add 32
- • °F to °C: Subtract 32, then divide by 1.8
- • Quick estimate: Double °C and add 30 for rough °F
Volume Tips
- • Litres to gallons (US): Divide by 3.8
- • US cups to mL: Multiply by 237 (≈240 mL)
- • AU cups to mL: Multiply by 250 (exact)
Frequently Asked Questions
Why does Australia use the metric system? ▼
Australia officially adopted the metric system in 1970 as part of a global movement towards standardisation.
The metric system is simpler to use (base 10), easier to teach, and facilitates international trade and
scientific collaboration. The transition was completed by 1988, making Australia one of the first
English-speaking countries to fully metricate.
What's the difference between US and UK gallons? ▼
A US gallon is approximately 3.785 litres, while a UK (Imperial) gallon is about 4.546 litres - roughly
20% larger. This difference also affects related measurements like pints and fluid ounces. When converting
fuel economy figures, always check whether they use US or UK gallons, as this significantly affects MPG calculations.
Why is the Australian tablespoon different from the US tablespoon? ▼
The Australian tablespoon is 20 mL, while the US tablespoon is only 15 mL (about 25% less). This difference
stems from different historical standards. When following American recipes, you'll need to adjust - for every
4 Australian tablespoons, use 5 when converting to US measurements, or simply use 15 mL measures for US recipes.
How do I convert height from feet and inches to centimetres? ▼
First, convert everything to inches (multiply feet by 12 and add any remaining inches). Then multiply by
2.54 to get centimetres. For example, 5'10" = (5 × 12) + 10 = 70 inches × 2.54 = 177.8 cm. Alternatively,
you can convert feet to cm (multiply by 30.48) and inches to cm (multiply by 2.54), then add them together.
What is a hectare and how does it compare to acres? ▼
A hectare (ha) is 10,000 square metres, or roughly the size of a rugby field. One hectare equals approximately
2.47 acres. In Australian real estate, rural and agricultural properties are typically measured in hectares,
while residential land is often quoted in square metres. One acre is about 4,047 square metres.
How accurate are these conversions? ▼
Our converter uses internationally standardised conversion factors that are accurate to at least 6 significant
figures. For everyday purposes (cooking, DIY projects, travel), this level of precision is more than sufficient.
For scientific or engineering applications requiring higher precision, please verify with official standards
from the National Measurement Institute of Australia.