# How do I convert lbs to oz?

Converts pounds (lb) to ounces (oz) and back, with the exact unit definitions.

- Page: https://www.acalculator.org/convert/lbs-to-oz
- JSON spec: https://www.acalculator.org/convert/lbs-to-oz.json
- Version: 3e83a5966fd6

## Default answer

Example with the default inputs (Pounds (lb) 1): 1 lb = 16 oz.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Pounds (lb) | The amount in pounds to convert. |
| result | Ounces (oz) | The same amount in ounces. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Pounds (lb) | The amount in pounds to convert. |
| result | Ounces (oz) | The amount in ounces. |

## Method

oz = lb × 16

## Assumptions

- 1 pound = 16 ounces, from the exact definitions in NIST SP 811.
- Ounces here are avoirdupois ounces, a weight: 1 oz = 1/16 lb = 28.349523125 g. A US fluid ounce is a volume.
- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up; an answer of 1 billion or more shows at most 15 significant digits.

## Worked examples

1. value = 1 gives result = 16. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
2. value = 2.5 gives result = 40. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.
3. result = 40 gives value = 2.5. Source: Exact unit definitions in NIST SP 811 (2008), Appendix B.8.

## FAQ

### How many ounces are in a pound?

1 pound is 16 ounces, from the exact unit definitions (NIST SP 811).

### How do I convert lbs to oz?

Multiply by 16: oz = lb × 16. For example, 1 lb × 16 = 16 oz.

### How do I convert oz back to lbs?

Multiply by 0.0625, or type the ounces into the second box and the converter works it out. 1 ounce is 0.0625 pounds.

### Is an ounce here a weight or a volume?

A weight: the avoirdupois ounce, 1/16 of a pound (28.349523125 g exactly). A US fluid ounce (29.57 mL) measures volume, as on cups-to-ounces pages.

### What is 2.5 lbs in ounces?

40 oz: 2.5 × 16. In pounds and ounces that is 2 lb 8 oz.

### How many ounces are in half a pound?

8 oz. A quarter pound is 4 oz.

## Sources

- NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B.8: Factors for Units Listed Alphabetically (bold factors are exact), retrieved 2026-10-18. https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8
- NIST SP 811 (2008), footnotes to Appendix B: 1 lb = 0.45359237 kg exactly (footnote 22); 1 lbf = 4.4482216152605 N exactly with standard gravity, 9.80665 m/s² (footnote 23), retrieved 2026-10-18. https://www.nist.gov/pml/special-publication-811/nist-guide-si-footnotes