Pounds to Ounces Converter

Pounds to Ounces

Convert pounds (lb) to ounces (oz). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.

The Formula

`` ounces = pounds × 16 pounds = ounces × 0.0625 `

One pound is 16 ounces, and one ounce is 0.0625 pounds.

Conversion Table

Pounds	Ounces
1 lb	16 oz
2 lb	32 oz
5 lb	80 oz
10 lb	160 oz
25 lb	400 oz
50 lb	800 oz
100 lb	1,600 oz
500 lb	8,000 oz
1,000 lb	16,000 oz

The Other Direction

Ounces	Pounds
1 oz	0.0625 lb
2 oz	0.125 lb
5 oz	0.3125 lb
10 oz	0.625 lb
25 oz	1.5625 lb
50 oz	3.125 lb
100 oz	6.25 lb
500 oz	31.25 lb
1,000 oz	62.5 lb

What Each Unit Is

Pounds (lb) — exactly 0.45359237 kilograms, by the 1959 international agreement. The Roman libra — which is why its symbol is lb — refined through the English avoirdupois system.

Ounces (oz) — one sixteenth of a pound, or exactly 28.349523125 grams. From uncia, one twelfth — of the Roman libra, before avoirdupois moved it to one sixteenth.

A Sense of Scale

• A bag of sugar is 2 lb
• A newborn is 6–9 lb
• US body weight is given in pounds
• A slice of bread is about 1 oz
• A tennis ball is 2 oz
• US recipes use ounces for dry goods

Precision

The factor 16 is exact by international agreement, not a rounded approximation. Any imprecision in a result comes from your input, not the conversion.

Watch Out For

• A fluid ounce measures volume, not mass, and the two are only interchangeable for water by coincidence of scale.

In Code

`javascript const poundToOunce = (value) => value * 16; ``

Where This Conversion Comes Up

• Cooking
• Shipping
• Fitness
• Medicine
• Manufacturing

How Many Decimals Do You Need?

Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 lb with the factor truncated at each decimal place:

Decimals kept	Factor	137 lb becomes	Error
0	16	2,192	—
1	16	2,192	—
2	16	2,192	—
3	16	2,192	—
4	16	2,192	—

A rule that holds for any conversion: round once, at the end. Rounding the factor and then multiplying compounds the error through every subsequent calculation, while carrying full precision and rounding the final answer does not.

The right number of significant figures is set by your input, not by the converter. If you measured pounds to three significant figures, the answer in ounces is only good to three — writing more digits claims precision the measurement never had.