Unit Pair Converters Basics: Exact Factors and Reverse Mode
Pair converters focus on one high-intent conversion (and its reverse) with documented exact factors—kilograms↔pounds, centimeters↔feet/inches, Celsius↔Fahrenheit, liters↔US gallons, and more. They complement the general unit converter instead of replacing it.
Why Pair Pages Exist
Searchers often want a single job done clearly: kg to lbs, cm to feet and inches, or psi to bar. A dedicated page can explain the exact constant, show worked examples, and keep reverse mode one click away without a category dropdown.
Hub converters
| Pair | Forward | Notes |
|---|---|---|
| kg ↔ lb | kg → lb | Exact avoirdupois pound |
| cm ↔ ft/in | cm → ft + in | Inches < 12 on reverse |
| °C ↔ °F | °C → °F | Absolute-zero guard |
| L ↔ US gal | L → US gal | Not UK imperial |
| mm ↔ in | mm → in | Exact 25.4 mm |
| m² ↔ ft² | m² → ft² | International foot |
| acres ↔ ft² | acres → ft² | 43,560 ft²/acre |
| psi ↔ bar | psi → bar | Pascal-based |
How reverse mode works
Pick direction
Forward is the named pair; reverse swaps from/to units.
Enter the from-value
Non-negative for lengths, masses, volumes, areas, and pressures; temperatures allow negatives above absolute zero.
Read both sides
Result details show both units so you can verify round-trips.
Start with a high-traffic pair
Try kilograms to pounds, then explore the rest of the hub:
Open Kg to Lbs Calculator