Weight Converter

Convert weight units (kg, lbs, oz).

Weight Converter

Weight Converter

Everything you need to know

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About the Weight Converter

Weight and mass measurements vary dramatically across countries and industries. The United States uses pounds and ounces, most of the world uses kilograms and grams, and the UK still uses stones for body weight. Our weight converter handles all major units instantly.

Supported conversions:

  • Pounds (lb) ↔ Kilograms (kg)
  • Ounces (oz) ↔ Grams (g)
  • Stones (st) ↔ Pounds/Kilograms
  • Tons (US/Metric/Imperial) ↔ Any unit
  • Milligrams (mg) ↔ Grams
  • Micrograms (mcg) ↔ Milligrams

Key Conversion Factors

From To Multiply By
Pounds (lb) Kilograms (kg) 0.453592
Kilograms (kg) Pounds (lb) 2.20462
Ounces (oz) Grams (g) 28.3495
Grams (g) Ounces (oz) 0.035274
Stones (st) Pounds (lb) 14
Stones (st) Kilograms (kg) 6.35029
Metric tons (t) Kilograms (kg) 1,000
US tons (short) Pounds (lb) 2,000
Imperial tons (long) Pounds (lb) 2,240

Quick Reference Tables

Pounds to Kilograms

Pounds Kilograms
1 lb 0.45 kg
5 lb 2.27 kg
10 lb 4.54 kg
25 lb 11.34 kg
50 lb 22.68 kg
100 lb 45.36 kg
150 lb 68.04 kg
200 lb 90.72 kg

Kilograms to Pounds

Kilograms Pounds
1 kg 2.20 lb
5 kg 11.02 lb
10 kg 22.05 lb
25 kg 55.12 lb
50 kg 110.23 lb
75 kg 165.35 lb
100 kg 220.46 lb

Ounces to Grams (Cooking)

Ounces Grams
1 oz 28 g
2 oz 57 g
4 oz 113 g
8 oz 227 g
16 oz (1 lb) 454 g

Common Weight References

Item Weight
Paperclip ~1 gram
AA battery ~23 grams
Smartphone ~150-200 grams
Basketball ~620 grams (22 oz)
House cat 4-5 kg (9-11 lb)
Bowling ball 7-8 kg (15-16 lb)
Adult human (male) 70-90 kg (155-200 lb)
Adult human (female) 55-75 kg (120-165 lb)
Suitcase (packed) 20-30 kg (44-66 lb)
Golden Retriever 25-35 kg (55-75 lb)
Motorcycle 150-250 kg (330-550 lb)
Compact car 1,200-1,500 kg (2,600-3,300 lb)
African elephant 4,000-7,000 kg (4-7 metric tons)

Body Weight Around the World

Country Average Male Weight Average Female Weight
United States 90 kg (198 lb) 77 kg (170 lb)
UK 84 kg (185 lb) 70 kg (154 lb)
Japan 68 kg (150 lb) 53 kg (117 lb)
Germany 85 kg (187 lb) 69 kg (152 lb)
India 60 kg (132 lb) 52 kg (115 lb)
Australia 86 kg (190 lb) 72 kg (159 lb)
Brazil 75 kg (165 lb) 65 kg (143 lb)

Cooking and Baking Conversions

Common Ingredient Weights

Ingredient 1 Cup 1 Tablespoon 1 Teaspoon
All-purpose flour 120 g (4.25 oz) 8 g (0.28 oz) 3 g (0.1 oz)
Granulated sugar 200 g (7 oz) 12 g (0.4 oz) 4 g (0.14 oz)
Brown sugar (packed) 220 g (7.75 oz) 14 g (0.5 oz) 5 g (0.18 oz)
Butter 227 g (8 oz) 14 g (0.5 oz) 5 g (0.17 oz)
Honey 340 g (12 oz) 21 g (0.75 oz) 7 g (0.25 oz)
Milk 240 g (8.5 oz) 15 g (0.5 oz) 5 g (0.17 oz)

Shipping and Logistics

Dimensional Weight (Volumetric Weight)

Shipping carriers charge by actual weight or dimensional weight, whichever is greater:

Formula: Dimensional Weight = (Length × Width × Height) ÷ Divisor

Carrier/Service Divisor (inches) Divisor (cm)
UPS/FedEx (domestic) 139 5,000
UPS/FedEx (international) 139 5,000
USPS 166 6,000
DHL 139-166 5,000-6,000

Example: Box measures 20" × 15" × 12", actual weight 8 lb

  • Dimensional weight = (20 × 15 × 12) ÷ 139 = 25.9 lb
  • Billed at 26 lb (dimensional weight wins)

Weight in Science and Medicine

Metric Prefixes

Prefix Symbol Factor Example
Kilogram kg 10³ 1 kg = 1,000 g
Gram g 10⁰ Base unit
Milligram mg 10⁻³ 1 mg = 0.001 g
Microgram mcg/μg 10⁻⁶ 1 mcg = 0.000001 g
Nanogram ng 10⁻⁹ 1 ng = 0.000000001 g

Medication Dosing

Medications are dosed by weight, making accurate conversion critical:

Example: Child weighs 35 lb, medication dose is 10 mg/kg

  • 35 lb × 0.453592 = 15.88 kg
  • Dose: 15.88 kg × 10 mg/kg = 158.8 mg

Frequently Asked Questions

What's the difference between mass and weight?

Mass is the amount of matter (constant everywhere). Weight is the force of gravity on that mass (varies by location). On the Moon, you weigh 1/6 as much but have the same mass.

Why does the UK use stones for body weight?

Tradition. One stone = 14 pounds. It's less common now but still used in everyday conversation (e.g., "I weigh 11 stone").

How do I convert my luggage weight for international flights?

Most airlines outside the US list limits in kilograms. 23 kg (standard checked bag limit) = 50.7 lb. 7 kg (carry-on limit) = 15.4 lb.

What's a "short ton" vs. "long ton" vs. "metric ton"?

  • Short ton (US): 2,000 lb (907 kg)
  • Long ton (UK): 2,240 lb (1,016 kg)
  • Metric ton (tonne): 1,000 kg (2,205 lb)

Why do recipes use weight instead of volume?

Weight is more accurate. A cup of flour can vary by 20% depending on how it's packed. 120 grams of flour is always 120 grams.