Pound vs kilogram exchange rate?

1 pound = 0.45359237 kg exactly (defined internationally). 1 kg = 2.20462 lb (approximately). The conversion is exact in both directions, with no rounding error in the conversion factor itself. The calculator uses these exact values.

What's the difference between mass and weight?

Strictly, mass is the amount of matter (constant); weight is the force gravity exerts (varies by gravity). On Earth, 1 kg has weight ~9.81 N (Newton). In everyday English, 'weight' usually means mass, which is why 'weight' is measured in kg. The calculator handles 'weight' colloquially as mass.

Why are there 'short ton' and 'long ton'?

Short ton (2000 lb, ~907 kg) is the US ton; long ton (2240 lb, ~1016 kg) is the UK ton; metric tonne is 1000 kg (~2205 lb). Three different 'tons' depending on country and context. Make sure you're using the right one — the difference matters in shipping, agriculture, and industry.

Troy ounce (used for precious metals: gold, silver, platinum) = 31.1035 grams ≈ 480 grains. Different from avoirdupois ounce (regular weight, ~28.35g). Gold prices are quoted per troy ounce. When buying gold, ensure you're calculating in troy ounces, not regular ounces.

Can I convert between weight and mass?

Effectively yes (on Earth). 1 lb mass weighs 1 lbf (pound-force) on Earth. For Newtonian physics distinguishing them: 1 kg mass × 9.81 m/s² = 9.81 N weight. For everyday conversions, the calculator treats 'weight' as colloquial mass.

What's the largest unit?

Most calculators include up to metric tonne (1000 kg / 2205 lb) and long/short tons. For very large weights (cargo ships, planetary masses), use scientific notation: 1 megaton = 1 million tons = 10^9 kg. For planetary scales, kilograms or solar masses (not weight units) are more practical.

Is the conversion done locally?

Yes. All calculations happen in your browser using exact conversion factors. No server interaction; useful for confidential weight data (medical, agricultural, industrial).

Weight Converter

Convert between kilograms, pounds, ounces, grams, and more weight units online. Free mass converter with instant calculations.

Calculators Unit Converters

Instant results

Enter value to convert

Conversions

Milligrams

1000000mg

Grams

1000g

Kilograms

1kg

Ounces

35.273991oz

Pounds

2.204624lb

Stones

0.157473st

Metric Tons

0.001t

How to Use Weight Converter

Enter weight value

Type the weight and select source unit (kg, lb, oz, g, etc.).

Choose target unit

Select destination unit. Result appears instantly with proper precision.

Compare across systems

Verify metric ↔ imperial conversions. Helpful for fitness apps, cooking recipes, shipping, and international communication.

Note the unit context

Different industries use different units (troy oz for precious metals, stones for body weight in UK). Use the right unit for your context.

When to Use Weight Converter

Cooking and recipe scaling

International recipes use different units. US recipes use cups (volume) and lb/oz (weight); European recipes use grams. Convert recipes accurately when cooking dishes from different cuisines, or when scaling recipes up/down.

Fitness and weight tracking

Track weight loss/gain across different scales. UK uses stones (1 stone = 14 lb); US uses pounds; metric users use kilograms. Same weight, different numbers — the converter ensures consistent tracking.

Shipping and logistics

International shipping uses kg primarily; US domestic uses lb. Calculate shipping costs accurately by converting between systems. Avoid surprise charges from underestimated weights.

Industrial and agricultural weights

Agriculture uses tons (sometimes ambiguous between short, long, metric). Industries use specific units (carats for diamonds, troy ounces for precious metals). The converter handles these specialized contexts.

Weight Converter Examples

Body weight conversion

Input

150 lb

Output

68.04 kg = 10 stones 10 lb = 2400 oz

Standard adult body weight in different systems. Useful for fitness apps that mix systems, medical contexts (drug dosing in kg), and international travel where weight is reported in different units.

Cooking weight

Input

2 cups flour ≈ 250 g

Output

8.8 oz = 0.55 lb

Cups (volume) to grams (weight) is approximate since it depends on the ingredient density. The calculator converts weights only; for volume-to-weight, refer to ingredient-specific charts (flour, sugar, water all weigh differently per cup).

Precious metals

Input

1 troy ounce gold

Output

31.10 g = 1.097 oz (avoirdupois)

Troy ounce (precious metals) is heavier than regular ounce (food, weight). Always use troy oz when buying gold/silver. Difference: 31.10g (troy) vs 28.35g (avoirdupois).

Tips & Best Practices for Weight Converter

1.Always specify the unit clearly in international communication. '5 tons' could mean 4.5 metric tons or 5 short tons or 5.6 long tons depending on context.
2.For precious metals, always use troy ounces. Buying 'an ounce of gold' at avoirdupois weight (28.35g) when the seller means troy (31.1g) is a 9% discount unintentionally.
3.When tracking body weight, pick one system and stick with it. Switching between systems (kg one week, lb the next) makes it harder to see trends.
4.Cooking weight conversions are simpler than volume conversions (which depend on ingredient). Weight is universal: 100g of any substance = 100g.
5.Postal services calculate shipping by weight AND dimensional weight (volume × density factor). Knowing both helps optimize shipping cost.
6.Common reference points: 1 kg ≈ 2.2 lb, 1 lb ≈ 0.45 kg, 1 stone = 14 lb. Helps quickly estimate without a calculator.

Frequently Asked Questions

Common units: kilograms (kg), grams (g), milligrams (mg), pounds (lb), ounces (oz), tonnes (metric ton, 1000 kg), short tons (US, 2000 lb), and long tons (UK, 2240 lb). Also: stones (UK weight, 14 lb), troy ounces (precious metals, 31.1g vs 28.35g for regular oz).

Weight Converter

How to Use Weight Converter

Enter weight value

Choose target unit

Compare across systems

Note the unit context

When to Use Weight Converter

Cooking and recipe scaling

Fitness and weight tracking

Shipping and logistics

Industrial and agricultural weights

Weight Converter Examples

Body weight conversion

Cooking weight

Precious metals

Tips & Best Practices for Weight Converter

Frequently Asked Questions

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