Conversion Methodology
Where our numbers come from, and what we round.
One stored factor per unit
Every unit on this site stores its size in a base unit: kilograms for weight, liters for volume, meters for length and square meters for area. A conversion is always value → base unit → target unit. Because a pair and its reverse read the same two stored numbers, pages such as pounds to kilograms and kilograms to pounds cannot disagree.
Unit standards we follow
- Pound and foot: the international yard and pound agreement of 1959 — 1 lb = 0.45359237 kg and 1 ft = 0.3048 m, both exact by definition.
- Ounce (weight): exactly 1/16 of a pound.
- US liquid gallon: exactly 231 cubic inches = 3.785411784 liters. The quart is a quarter of it, the fluid ounce is 1/128 of it, and the US customary cup is 8 fluid ounces.
- Metric units: SI prefixes — 1 g = 0.001 kg, 1 mL = 0.001 L, 1 cm = 0.01 m.
- Square foot: 0.3048 × 0.3048 = 0.09290304 m², the length factor applied twice.
Where a unit has more than one meaning, the page says which one it uses. US liquid units are the default on volume pages, and the Imperial difference is stated on the page rather than left for you to discover.
Factors used by the published converters
| Converter | Multiply by |
|---|---|
| Milliliters to Ounces | 1 mL = 0.033814022702 fl oz |
| Grams to Pounds | 1 g = 0.002204622622 lb |
| Fluid Ounces to Cups | 1 fl oz = 0.125 cup |
| Quarts to Gallons | 1 qt = 0.25 gal |
| Square Meters to Square Feet | 1 m² = 10.76391041671 ft² |
| Liters to Gallons | 1 L = 0.264172052358 gal |
| Feet to Centimeters | 1 ft = 30.48 cm |
| Pounds to Ounces | 1 lb = 16 oz |
| Pounds to Kilograms | 1 lb = 0.45359237 kg |
| Kilograms to Pounds | 1 kg = 2.204622621849 lb |
Rounding
Results show four decimal places by default, and you can change that on any converter. We round only for display: the calculation itself keeps full precision, and trailing zeroes are removed so an answer reads the way a person would say it. Where a factor does not terminate — kilograms to pounds, for example — the page says so instead of implying the result is exact.
Corrections
If a number here looks wrong, it matters more to us than any other bug. Tell us what you entered and what you expected via the about page. We check the reported value against the defining standard, fix the stored factor if it is wrong, and the fix reaches every page that uses it at once.
We do not add invented review dates or fake author credentials to these pages. The definitions above have not changed since 1959 and 1964, and pretending otherwise would be dishonest.