Sixteen, Because Halving Is How Food Is Sold
The metric system chose 10 because it is decimal. The imperial system chose 16 because it halves: a pound divides into two half-pounds, four quarter-pounds, eight 2-oz servings, sixteen 1-oz servings — and every one of those divisions is a whole number. That is not an accident; it matches the reality of how food is cut and portioned. A butcher's quarter-pound patty, a deli's quarter-pound slice batch, a cheese block scored into 1-oz servings — all of them are clean under 16. Multiply a pound by 16 and the entire US serving-size ladder falls out.
ounces = pounds × 16
1 lb = 16 oz exactly
Definitional — the avoirdupois ounce is one sixteenth of the pound, zero uncertainty.
Pounds in the Language of Portions
| pounds | ounces | Context |
|---|---|---|
| 0.25 lb | 4 oz | Quarter-pound burger patty. |
| 0.5 lb | 8 oz | One stick of butter, half-pound cut. |
| 0.75 lb | 12 oz | Classic restaurant steak. |
| 1 lb | 16 oz | Deli pound, pound cake, porterhouse. |
| 2 lb | 32 oz | Family cheese block and yogurt tub. |
The 0.5 lb row is the one baked into every American refrigerator: butter arrives as 1-lb boxes containing two 8-oz sticks, each stick printed with tablespoon marks. That is why recipes almost never say "half a pound of butter" — they say "one stick", and one stick is 8 oz is 0.5 lb is 227 g, all the same quantity at the center of the weight hub's conversion web. When a recipe from Europe asks for 227 g and the US kitchen has sticks, the whole chain — pound, ounce, gram — resolves through this one page.
Engineering Context
The reverse direction is ounces to pounds. The ounce connects to the metric side through oz to grams and grams to ounces, and to the larger scale through grams to lbs, lbs to grams, and kg to lbs. Since the ounce is a weight, not a volume, it pairs with the fluid-ounce conversions on the volume hub — see ml to fl oz — for the cooking boundary where the two get confused. Everything returns to the weight hub.
More: oz to lb · oz to g · g to lb · Weight Hub
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Frequently Asked Questions
How do I convert pounds to ounces?
Multiply by 16: ounces = pounds × 16. Half a pound of butter is 0.5 × 16 = 8 oz; a 2 lb block of cheese is 32 oz. The factor is exact because the avoirdupois ounce is one sixteenth of the pound.
Why is a pound divided into 16 ounces and not 10?
Because 16 divides evenly by 2, 4, and 8 — a pound can be halved four times and stay whole (8, 4, 2, 1 oz). That halving convenience is why the imperial system kept 16: it matches how food is actually sold, cut, and portioned. The metric gram, by contrast, is decimal because it divides by 10 and 100.
How many ounces are in a pound of butter?
16 oz — and an American stick of butter is half that, 8 oz, which is why recipes call for 'one stick' instead of 'half a pound'. A pound block of butter, sold in some markets, is exactly the full 16 oz. In grams that same pound is 453.6 g, so a 16 oz block and a 454 g block are the same butter in two label systems.
More: oz to lbs · oz to grams · Weight Hub