Metric and Imperial Conversion Guide

Metric and imperial units often appear together in product pages, travel plans, property listings and older reference material. The safest approach is to convert from the stated unit into the unit you actually need, then keep enough decimal places for the decision in front of you. For many everyday tasks, a rounded answer is fine; for measured materials, shipping or technical specifications, use the full result from the calculator.

Length and Distance

Length conversions are built around exact definitions. One inch is exactly 2.54 centimetres, one foot is 12 inches, one yard is 3 feet and one mile is 1,609.344 metres. That means a 72-inch bookcase is 182.88 cm, while a 5-mile run is 8.04672 km. Use the length converter when you need to move between small product dimensions and larger travel distances.

Weight and Mass

The pound is defined as exactly 0.45359237 kilograms, so 10 lb is 4.5359237 kg and 20 kg is about 44.092 lb. This matters for airline luggage, parcel services and gym equipment, where a small difference can change whether an item fits a limit. The weight converter keeps the calculation visible so you can copy the result into a booking form or checklist.

Area

Area conversions are easy to underestimate because both dimensions are converted. One square metre is about 10.7639 square feet, and one acre is 4,046.8564224 square metres. A flat listed as 850 square feet is about 78.97 square metres, which is a more useful figure when comparing homes in countries that publish floor plans in metric units.

Speed

Miles per hour and kilometres per hour are common on roads, fitness apps and vehicle specifications. One mph is 1.609344 km/h, so 60 mph is about 96.56 km/h. The reverse is also useful: 100 km/h is about 62.14 mph. For boating or aviation contexts, knots use nautical miles per hour, so convert them separately rather than treating them as statute miles.

Return to the main unit converter for all categories, or use the focused area, speed and pressure pages for narrower reference tables.