Imperial Units Converter
Free imperial units converter for length, weight, volume, area, and temperature. Convert in, ft, yd, mi, lb, oz, gal, Fahrenheit to metric units instantly.
About This Calculator
The Imperial Units Converter helps you convert between imperial and metric units across five categories: length, weight, volume, area, and temperature. Whether you are a student learning unit conversions, a cook following an international recipe, a DIY enthusiast working on a home project, or a professional in construction or shipping, this tool provides fast and accurate conversions for all common imperial measurements.
Select a category — Length, Weight, Volume, Area, or Temperature — then enter your value and choose the imperial unit you want to convert from. The converter supports all major imperial units: inches, feet, yards, miles, ounces, pounds, stones, cubic inches, cubic feet, gallons, quarts, pints, cups, fluid ounces, square inches, square feet, square yards, acres, and Fahrenheit. Results display in your chosen target unit along with a complete breakdown showing the equivalent value in every available unit for that category.
Our converter uses precise conversion factors based on international standards. Length conversions use 1 inch = 2.54 cm (exact), weight uses 1 lb = 0.45359237 kg (exact), and area and volume are derived from these linear conversions. Temperature conversions use the standard formulas: °C = (°F − 32) × 5/9 and K = °C + 273.15.
Regional Notes
United States: The US Customary system (closely related to imperial) is the standard for everyday measurements. Common units used include inches, feet, miles, pounds, fluid ounces, and Fahrenheit. Our converter defaults to US customary volume units (US gallon = 3.785 L, US pint = 473 ml).
United Kingdom: The UK uses a mix of metric and imperial units. Road distances use miles and yards, beer is sold in pints (UK pint = 568 ml), and body weight is often measured in stones and pounds. Temperature is officially Celsius but many people still use Fahrenheit informally.
India: India uses the metric system officially, but imperial units are still encountered in real estate (sq ft), clothing (inches for waist/chest), and some construction materials. This converter helps bridge the gap between metric and imperial for everyday Indian use.
Frequently Asked Questions
What imperial units of length can I convert?
You can convert between inches, feet, yards, miles, and their metric equivalents including millimeters, centimeters, meters, and kilometers. Common conversions include inches to centimeters (1 in = 2.54 cm), feet to meters (1 ft = 0.3048 m), and miles to kilometers (1 mi = 1.609 km).
How do I convert imperial weight units?
Our imperial weight converter handles ounces (oz), pounds (lb), stones, and their metric equivalents grams and kilograms. Key conversions: 1 lb = 16 oz = 0.4536 kg, 1 stone = 14 lb = 6.35 kg. This is useful for cooking recipes, shipping weights, and personal body weight tracking.
Can I convert Fahrenheit to Celsius?
Yes, the temperature converter converts Fahrenheit to Celsius and Kelvin. The formula is T(°C) = (T(°F) - 32) × 5/9. For example, 212°F = 100°C (boiling point) and 32°F = 0°C (freezing point). This is essential for cooking, weather, and scientific applications.
What volume conversions are available?
Convert between cubic inches, cubic feet, gallons, quarts, pints, cups, fluid ounces, and metric units like milliliters and liters. Key relationships: 1 gallon = 4 quarts = 8 pints = 16 cups = 128 fl oz = 3.785 L. Note that US and UK gallons differ slightly; our calculator uses US customary units.
How do I convert imperial area units?
Our area converter handles square inches, square feet, square yards, acres, and metric units including square meters, square kilometers, and hectares. Key conversions: 1 sq ft = 144 sq in, 1 acre = 43,560 sq ft = 0.4047 hectares. Useful for real estate, construction, and land measurement.
Is this imperial units converter free to use?
Yes, the Imperial Units Converter on Calculy is completely free to use with no registration or limits. You can perform unlimited conversions across all five categories — length, weight, volume, area, and temperature — and share your results via URL.
How do I convert between imperial units without a calculator?
For length, remember 1 ft = 12 in, 1 yd = 3 ft, 1 mi = 1,760 yd. For weight, 1 lb = 16 oz and 1 US ton = 2,000 lb. For volume, 1 gal = 4 qt = 8 pt = 16 c = 128 fl oz. For area, square the linear conversions: 1 sq ft = 144 sq in. For temperature, use °C = (°F - 32) × 5/9.
What is the difference between US and UK imperial units?
While both systems share many units, there are key differences. The US pint (473 ml) is smaller than the UK pint (568 ml). US gallons (3.785 L) differ from UK imperial gallons (4.546 L). US fluid ounces (29.57 ml) also differ from UK fl oz (28.41 ml). Our calculator uses US customary units for volume.