Metric to Imperial Converter & Complete Reference: Units, Tables, Formulas
Comprehensive guide to converting between metric and imperial systems. Includes history, key differences, common units, conversion formulas, tables, and practical examples for science, travel, cooking, and more.
Introduction
The metric and imperial systems are two major systems of measurement used around the world. The metric system is decimal-based and used by most countries, while the imperial system is primarily used in the United States and a few other countries. Understanding how to convert between these systems is essential for international travel, science, engineering, and daily life.
History and Overview
- Metric System: Developed in France in the late 18th century. Based on powers of ten (meter, liter, gram).
- Imperial System: Originated in the British Empire. Includes feet, inches, pounds, gallons, etc.
Key Differences
- Metric units are decimal-based (e.g., 1 meter = 100 centimeters).
- Imperial units are not decimal-based (e.g., 1 foot = 12 inches).
- Metric is standard in science and most of the world; imperial is common in the US for daily life.
Common Units
| Quantity | Metric Unit | Imperial Unit |
|---|---|---|
| Length | meter (m) | inch (in), foot (ft), yard (yd), mile (mi) |
| Mass | gram (g), kilogram (kg) | ounce (oz), pound (lb), stone (st) |
| Volume | liter (L), milliliter (mL) | fluid ounce (fl oz), pint (pt), quart (qt), gallon (gal) |
| Temperature | Celsius (°C) | Fahrenheit (°F) |
Conversion Formulas
- Length:
- 1 inch = 2.54 centimeters
- 1 foot = 0.3048 meters
- 1 yard = 0.9144 meters
- 1 mile = 1.60934 kilometers
- 1 centimeter = 0.3937 inches
- 1 meter = 3.2808 feet
- 1 kilometer = 0.6214 miles
- Mass:
- 1 ounce = 28.3495 grams
- 1 pound = 0.453592 kilograms
- 1 stone = 6.35029 kilograms
- 1 gram = 0.035274 ounces
- 1 kilogram = 2.20462 pounds
- Volume:
- 1 fluid ounce (US) = 29.5735 milliliters
- 1 pint (US) = 473.176 milliliters
- 1 quart (US) = 946.353 milliliters
- 1 gallon (US) = 3.78541 liters
- 1 milliliter = 0.033814 fluid ounces
- 1 liter = 33.814 fluid ounces
- Temperature:
- °F = (°C × 9/5) + 32
- °C = (°F − 32) × 5/9
Conversion Tables
Length
| Imperial | Metric |
|---|---|
| 1 inch | 2.54 cm |
| 1 foot | 30.48 cm |
| 1 yard | 0.9144 m |
| 1 mile | 1.609 km |
Mass
| Imperial | Metric |
|---|---|
| 1 ounce | 28.35 g |
| 1 pound | 0.454 kg |
| 1 stone | 6.35 kg |
Volume
| Imperial | Metric |
|---|---|
| 1 fl oz (US) | 29.57 mL |
| 1 pint (US) | 473 mL |
| 1 quart (US) | 946 mL |
| 1 gallon (US) | 3.785 L |
Practical Examples
- Convert 10 miles to kilometers: 10 × 1.60934 = 16.09 km
- Convert 5 kilograms to pounds: 5 × 2.20462 = 11.02 lbs
- Convert 2 liters to quarts (US): 2 × 1.05669 = 2.11 qt
- Convert 100°F to Celsius: (100 − 32) × 5/9 = 37.78°C
Tips for Accurate Conversion
- Always check which gallon, pint, or ounce is being used (US vs UK).
- Use a calculator or online tool for complex conversions.
- Round results appropriately for your application.
FAQ
- Why are there two systems? Historical reasons and regional preferences.
- Which system is better? Metric is easier for calculations; imperial is still common in the US.
- Can I use these conversions for cooking? Yes, but always check if the recipe uses US or UK units.
Frequently Asked Questions
What is the difference between metric and imperial systems?
The metric system is decimal-based and used worldwide, while the imperial system is used mainly in the US and a few other countries. Metric units are easier to convert and standard in science.
How do I convert inches to centimeters?
Multiply inches by 2.54 to get centimeters. For example, 10 inches × 2.54 = 25.4 cm.
Why are there different measurement systems?
Measurement systems evolved historically in different regions. The metric system was created for standardization and ease of use, while the imperial system is based on older British units.
Where are metric and imperial units used?
Metric is used in most countries and in science. Imperial is common in the US, UK (for some uses), and a few other places.