Weight Conversion Calculator
Use this weight conversion calculator to quickly convert between common metric and imperial weight units, including milligrams, grams, kilograms, ounces, pounds, stone and tonnes.
Whether you are checking body weight, comparing shipping weights, converting recipe measurements or working with product specifications, this calculator gives you a fast and simple way to switch between units.
Whether you are checking body weight, comparing shipping weights, converting recipe measurements or working with product specifications, this calculator gives you a fast and simple way to switch between units.
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Disclaimer: This calculator provides conversion results for general informational use only. Last checked/updated March 2026.
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How the Weight Conversion Calculator Works
This calculator converts weight measurements using standard, widely accepted conversion values. It supports both metric and imperial units and calculates accurate results based on the units selected.
Supported units include:
Supported units include:
It is useful for everyday, business and educational conversions where accuracy matters.
How to Use the Weight Conversion Calculator
Using the calculator is straightforward.
1. Select the unit you want to convert from
2. Select the unit you want to convert to
3. Enter your value
4. View the converted result instantly
The result updates automatically based on the units selected.
1. Select the unit you want to convert from
2. Select the unit you want to convert to
3. Enter your value
4. View the converted result instantly
The result updates automatically based on the units selected.
Common Weight Conversions
People often use a weight converter for situations like these:
Example 1: Health & Fitness (Imperial to Metric)
If you weigh 12 stone and 4 pounds and your doctor or a fitness app requires your weight in kilograms:
– First, convert the stone to pounds (12 × 14 = 168 lbs), adding the extra 4 lbs for a total of 172 lbs.
– Input 172 lbs into the calculator, which converts it to 78.01 kilograms. This is the standard medical measurement used across the UK and Europe.
Example 2: Travel & Luggage (Metric to Imperial)
If an airline states your maximum baggage allowance is 23 kilograms, but you use a traditional set of scales that only shows pounds:
– Input 23 kg into the calculator, which converts it to roughly 50.7 pounds.
– Knowing this exact allowance helps you avoid unexpected heavy baggage fees at the airport.
If you weigh 12 stone and 4 pounds and your doctor or a fitness app requires your weight in kilograms:
– First, convert the stone to pounds (12 × 14 = 168 lbs), adding the extra 4 lbs for a total of 172 lbs.
– Input 172 lbs into the calculator, which converts it to 78.01 kilograms. This is the standard medical measurement used across the UK and Europe.
Example 2: Travel & Luggage (Metric to Imperial)
If an airline states your maximum baggage allowance is 23 kilograms, but you use a traditional set of scales that only shows pounds:
– Input 23 kg into the calculator, which converts it to roughly 50.7 pounds.
– Knowing this exact allowance helps you avoid unexpected heavy baggage fees at the airport.
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Weight Units Explained
Milligram (mg)
A milligram is a very small unit of weight. It is commonly used for vitamins, medication, fine measurements and scientific data.
Gram (g)
A gram is a standard metric unit of weight. It is often used for food, ingredients, small packages and product specifications.
Kilogram (kg)
A kilogram is one thousand grams. It is one of the most commonly used weight units for people, parcels, luggage and general goods.
Ounce (oz)
An ounce is an imperial unit commonly used in cooking, food packaging and product labelling. Check out our Cooking Calculator here.
Pound (lb)
A pound is widely used in the United States and still appears in many everyday weight comparisons. It is also used alongside stone in body weight discussions.
Stone (st)
Stone is a traditional UK unit of weight often used when discussing body weight. One stone equals 14 pounds.
Tonne (t)
A tonne is a large metric unit equal to 1,000 kilograms. It is commonly used in freight, industry, agriculture and construction.
A milligram is a very small unit of weight. It is commonly used for vitamins, medication, fine measurements and scientific data.
Gram (g)
A gram is a standard metric unit of weight. It is often used for food, ingredients, small packages and product specifications.
Kilogram (kg)
A kilogram is one thousand grams. It is one of the most commonly used weight units for people, parcels, luggage and general goods.
Ounce (oz)
An ounce is an imperial unit commonly used in cooking, food packaging and product labelling. Check out our Cooking Calculator here.
Pound (lb)
A pound is widely used in the United States and still appears in many everyday weight comparisons. It is also used alongside stone in body weight discussions.
Stone (st)
Stone is a traditional UK unit of weight often used when discussing body weight. One stone equals 14 pounds.
Tonne (t)
A tonne is a large metric unit equal to 1,000 kilograms. It is commonly used in freight, industry, agriculture and construction.
Why Use A Weight Converter?
Weight units vary depending on the country, industry and context. A reliable converter helps avoid confusion and saves time when comparing measurements.
For example, one product may list weight in grams while another uses ounces. Health data may be shown in kilograms while some people still prefer pounds and stone. A weight conversion calculator makes those differences easier to manage.
For example, one product may list weight in grams while another uses ounces. Health data may be shown in kilograms while some people still prefer pounds and stone. A weight conversion calculator makes those differences easier to manage.
Weight Conversion Formulas
This calculator works by converting the chosen value into a base unit and then converting it into the selected output unit.
For example:
1 kilogram = 1,000 grams
1 pound = 453.59237 grams
1 stone = 14 pounds
That approach helps keep conversions consistent across all supported units.
For example:
1 kilogram = 1,000 grams
1 pound = 453.59237 grams
1 stone = 14 pounds
That approach helps keep conversions consistent across all supported units.
Popular Weight Conversions
Kilograms to pounds
This is one of the most common conversions for health, fitness and travel.
1 kilogram = 2.20462 pounds
Pounds to kilograms
Useful when reading international product details, body weight records or shipping information.
1 pound = 0.453592 kilograms
Pounds to stone
Common in the UK for body weight.
14 pounds = 1 stone
Grams to ounces
Often used in recipes, food packaging and retail products.
1 gram = 0.035274 ounces
Tonnes to kilograms
Useful for large commercial and industrial weights.
1 tonne = 1,000 kilograms
This is one of the most common conversions for health, fitness and travel.
1 kilogram = 2.20462 pounds
Pounds to kilograms
Useful when reading international product details, body weight records or shipping information.
1 pound = 0.453592 kilograms
Pounds to stone
Common in the UK for body weight.
14 pounds = 1 stone
Grams to ounces
Often used in recipes, food packaging and retail products.
1 gram = 0.035274 ounces
Tonnes to kilograms
Useful for large commercial and industrial weights.
1 tonne = 1,000 kilograms
About This Weight Conversion Calculator
This weight conversion calculator uses standard unit conversion values to provide accurate and reliable results. It allows you to quickly convert between common metric and imperial weight units including milligrams, grams, kilograms, ounces, pounds, stone and tonnes.
The calculator is designed to be simple to use and accessible across devices, making it suitable for everyday conversions such as cooking measurements, body weight comparisons, product weights and general unit conversions.
While suitable for general weight conversions, this tool should not be relied upon for specialised technical, engineering or scientific calculations without verification.
The calculator is designed to be simple to use and accessible across devices, making it suitable for everyday conversions such as cooking measurements, body weight comparisons, product weights and general unit conversions.
While suitable for general weight conversions, this tool should not be relied upon for specialised technical, engineering or scientific calculations without verification.
Frequently Asked Questions
What units can I convert with this calculator?
You can convert all of the main weight units including milligrams, grams, kilograms, ounces, pounds, stones and tonnes.
How many pounds are in a kilogram?
There are exactly 2.20462 pounds in one kilogram. For a quick mental calculation when you don’t have a tool to hand, you can multiply the kilograms by 2 and then add a little extra (10%) to get a rough estimate in pounds.
How many kilograms are in a pound?
There are 0.453592 kilograms in 1 pound.
How many pounds are in a stone?
There are 14 pounds in 1 stone.
Is stone still used in the UK?
Yes, while the UK officially adopted the metric system for most commercial and educational purposes, the ‘stone’ (equal to 14 pounds) remains the most common conversational measurement for human body weight across the UK and Ireland. However, it is rarely used in official medical or scientific settings anymore.
Disclaimer
This calculator provides weight conversion results for general informational purposes only.
Last checked/updated March 2026.
Last checked/updated March 2026.