Convert ounces (oz) to pounds (lb) and vice versa with our interactive weight conversion tool. Enter a value in either field, and the other updates instantly. View the exact formula, step-by-step calculation, and combined pounds-and-ounces result.
| Ounces (oz) | Pounds (lb) | Pounds & Ounces |
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The ounce (oz) and pound (lb) are the two most commonly used units of weight in the imperial and United States customary systems. The pound serves as the base unit, while the ounce is a subdivision: 1 pound equals exactly 16 ounces. This relationship has been standardized since the 1959 international yard and pound agreement, which defined the pound as exactly 0.45359237 kilograms, making the ounce exactly 28.349523125 grams.
Converting between ounces and pounds is a fundamental skill in cooking, shipping, fitness, and countless other domains. Whether you're scaling a recipe, calculating postage, tracking your body weight, or working on a DIY project, the ability to convert quickly and accurately is essential.
Core Conversion Formula
lb = oz ÷ 16 | oz = lb × 16
Both formulas are exact and derived from the definition of the imperial pound.
The conversion between ounces and pounds is linear and exact. Given that 1 lb = 16 oz, the conversion factor k = 16 is a constant. To convert ounces to pounds, we divide by 16: lb = oz / 16. Conversely, to convert pounds to ounces, we multiply by 16: oz = lb × 16.
This simple linear relationship means that the conversion is both commutative and associative. For example, 32 oz = 2 lb, 48 oz = 3 lb, and 0.5 lb = 8 oz. The relationship extends to fractional values as well: 1.5 lb = 24 oz, and 0.75 lb = 12 oz.
In the imperial system, weights are often expressed in combined form — for example, "1 lb 4 oz" rather than "1.25 lb" or "20 oz". This hybrid notation is common in grocery stores, recipes, and shipping labels. Our tool automatically calculates and displays this combined form for you.
The origins of the pound and ounce can be traced back to ancient Roman and medieval European systems. The libra (from which "lb" is derived) was a Roman unit of weight, while the uncia (the origin of "ounce") was one-twelfth of the libra. Over centuries, these units evolved, and the modern avoirdupois system — where 1 pound equals 16 ounces — was standardized in England during the 14th century.
In 1959, the international yard and pound agreement formally defined the pound as exactly 0.45359237 kilograms, giving the ounce a precise metric equivalent of 28.349523125 grams. This agreement aligned the imperial and metric systems, enabling accurate conversions between them.
Today, the ounce and pound remain in widespread use in the United States, the United Kingdom (for certain purposes), and various other countries. They are deeply embedded in everyday life — from food packaging to body weight measurement to postal services.
Imagine you're preparing a large batch of cookies for a family gathering. The recipe calls for 8 ounces of flour per batch, and you plan to make 3.5 batches. That's 28 ounces of flour total. How many pounds is that? Using the formula lb = oz ÷ 16, we get 28 ÷ 16 = 1.75 lb, or 1 lb 12 oz. Your kitchen scale likely measures in pounds and ounces, so knowing the combined form is essential. Our converter gives you both the decimal and combined forms instantly.
Below is a quick reference for common conversions between ounces and pounds. Use it as a handy guide for everyday measurements.
| Ounces (oz) | Pounds (lb) | Pounds & Ounces |
|---|---|---|
| 1 oz | 0.0625 lb | 0 lb 1 oz |
| 2 oz | 0.125 lb | 0 lb 2 oz |
| 4 oz | 0.25 lb | 0 lb 4 oz |
| 8 oz | 0.5 lb | 0 lb 8 oz |
| 12 oz | 0.75 lb | 0 lb 12 oz |
| 16 oz | 1.0 lb | 1 lb 0 oz |
| 20 oz | 1.25 lb | 1 lb 4 oz |
| 24 oz | 1.5 lb | 1 lb 8 oz |
| 32 oz | 2.0 lb | 2 lb 0 oz |
| 40 oz | 2.5 lb | 2 lb 8 oz |
| 48 oz | 3.0 lb | 3 lb 0 oz |
| 64 oz | 4.0 lb | 4 lb 0 oz |
While this tool focuses on ounces and pounds, it's useful to know the metric equivalents:
These relationships are defined by the international yard and pound agreement and are the basis for all precise conversions between imperial and metric weight units.