Use grams to pounds for a gram source or its pound-to-gram reverse mode. Use milligrams to pounds for a milligram input.
The exact avoirdupois relation is 1 lb = 453.59237 g = 453592.37 mg. A milligram is 1/1000 of a gram.
| Grams to pounds | Milligrams to pounds | |
|---|---|---|
| Controls | Direction selector with active grams or pounds field | Nonnegative milligrams |
| Default | 500 g to lb | 1000 mg to lb |
| Primary precision | Pounds up to 4 decimals; reverse grams up to 3 | Pounds up to 10 decimals |
| Forward details | Input grams, pounds-and-ounces, kilograms | Pounds, scientific notation, ounces, grams |
| Reverse details | Input pounds, kilograms, milligrams | No reverse mode |
Equal raw mass, different displays
1 g and 1000 mg are the same mass. Both give approximately 0.002204622621848776 lb before formatting. The gram form shows 0.0022 lbs, while the milligram form shows 0.0022046226 lb. Their displayed strings are not identical.
For its default 1000 mg, the milligram form also shows 2.204623e-3 lb in scientific notation and 1 g. That row helps make a small value readable; it does not add measurement precision.
Limits
These forms use avoirdupois mass, not troy units or liquid volume. Choose the source unit actually supplied and distinguish the longer primary readout from rounded detail/Copy values. They do not establish a material’s suitability or a measurement procedure.
Sources
NIST SP 811, unit definitions and Appendix B factors. The paired calculator controls and rounding described above are their current form behavior.