X-to-Y.com has a number of conversion calculators that will enable you to:
Convert Fahrenheit to Celsius Degrees Fahrenheit to Celsius e.g. 23 F to C

Convert Celsius to Fahrenheit Degrees Celsius to Fahrenheit e.g. 46 C to F

Convert Miles to Kilometres Miles to Km e.g. 123 m to km

Convert Kilometres to Miles Km to Miles e.g. 48 km to m

Convert Yards to Meters Yards to Meters e.g. 69 y to m

Convert Meters to Yards Meters to Yards e.g. 173 m to y

Soon X-to-Y.com will also offer Weight conversions, where you can convert Pounds to Kilograms, Kilograms to Pounds, and Area conversions, where you will be able to convert Acres to Square Kilometres, and Square Kilometres to Acres.