How Unit Pair Converters Work
One conversion job, an exact constant, and a reverse switch—built for search intent without a cluttered unit matrix.
How Unit Pair Converters Work
A pair converter answers a single question well: how many pounds in 70 kg, or how many centimeters in 5 ft 9 in. Under the hood each page multiplies or divides by a documented factor—or applies the Celsius/Fahrenheit affine transform—then exposes reverse mode so you can check the round trip.
Linear pairs vs temperature
Most pairs are linear: output = input × factor (or ÷ factor in reverse). Temperature is different: °F = °C×9/5+32, with a rejection below absolute zero. Height in feet and inches is linear in total inches, then split into whole feet plus a remainder.
Constants worth remembering
- 1 lb = 0.45359237 kg exactly
- 1 in = 25.4 mm exactly
- 1 US liquid gallon = 3.785411784 L
- 1 acre = 43,560 ft² (planning definition used here)
- 1 bar = 100,000 Pa
When to use the general converter
If you need yards, Kelvin, fluid ounces, or mixed categories in one sitting, use the general unit converter. Pair pages stay narrow on purpose for clarity and SEO.