Ounces to Pounds

Avoirdupois Mass Metrology & NIST SP 811 Standards

The avoirdupois pound is defined under international standards as exactly 16 ounces (0.45359237 kg):

• 1 Pound (lb): 16.0 Ounces (oz) = 453.592 g = 0.453592 kg

• 1 Ounce (oz): (1) / (16) lb = 0.0625 lbs = 28.3495 g

Primary Mass Equivalents Table

• 8 oz: = 0.500 lbs = (1) / (2) lb = 0 lbs 8 oz

• 16 oz: 1.000 lb = 1 lb 0 oz

• 24 oz: = 1.500 lbs = 1 (1) / (2) lbs = 1 lb 8 oz

• 32 oz: 2.000 lbs = 2 lbs 0 oz

• 36 oz: = 2.250 lbs = 2 (1) / (4) lbs = 2 lbs 4 oz

• 48 oz: 3.000 lbs = 3 lbs 0 oz

• 64 oz: 4.000 lbs = 4 lbs 0 oz

• 80 oz: 5.000 lbs = 5 lbs 0 oz

Equations

• Pounds (lbs) = Ounces (oz)16

• Ounces (oz) = Pounds (lbs) × 16

How to Use This Calculator

Enter your Weight Value to Convert (e.g. 36.0), Postal & Freight Benchmark — choose from Custom Weight Value, 8.0 oz (0.50 lb / USPS Large Flat Envelope), 16.0 oz (1.00 lb / 1st Class Package Limit), and Conversion Direction — choose from Ounces to Pounds (oz → lbs / divide by 16), Pounds to Ounces (lbs → oz / multiply by 16). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Conversion factors used in this calculator:

1 lb = 16 oz exact

Worked Example

A shipping parcel weighing 36 ounces converts to 2.25 pounds (exactly 2 pounds and 4 ounces) on a postal scale.

Understanding Your Result

Unit conversion precision: round to the same number of significant figures as your original measurement. Converting 6 feet to meters gives 1.8288 m — but if your measurement was approximate (±1 inch), expressing more than 2 decimal places is false precision. For international trade and technical specifications, SI units (meters, kilograms, liters) are the standard. US customary units (feet, pounds, gallons) differ from Imperial UK units: 1 US gallon = 3.785 L vs. 1 UK gallon = 4.546 L.