Need to convert kilograms to pounds? Grams to ounces? Or maybe you’re dealing with less common units like stones, carats, or grains?
This free weight unit converter handles it all. Enter any value, pick your unit, and get instant conversions across 35+ weight and mass units — from metric to imperial to traditional Japanese measurements.
No formulas to memorize. No math required. Just fast, accurate results.
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Weight (Mass) Unit Conversion Tool
Convert between various weight and mass units including Metric (SI prefixes), Imperial/US Customary, and Shakkan-ho.
| System | Unit | Value | Symbol |
|---|---|---|---|
| Enter a value and click “Calculate”. | |||
How to Use This Converter
Getting your conversion takes just a few seconds:
- Enter your weight value in the number field (decimals work too)
- Select the unit you’re converting FROM using the dropdown menu
- Click “Calculate” — or just wait, it updates automatically as you type
- View all conversions in the results table below
The table displays your value converted into every supported unit, organized by measurement system: Metric, Imperial/US Customary, and Shakkan-ho (Japanese).
Need to start over? Hit “Clear” to reset everything back to 1 kilogram.
Example Conversion
Let’s say you need to convert 5 pounds to other units:
- Enter: 5
- Select: Pound (lb)
- Result: The table instantly shows 5 lbs equals approximately 2.268 kg, 2,268 g, 80 oz, and 0.357 stone — plus 30+ other conversions.
Understanding Your Results
The results table is organized into three sections. Metric (SI Prefixes) includes everything from picograms to yottagrams, with common units like kilograms, grams, and metric tons. Imperial/US Customary covers pounds, ounces, stones, and tons used in the US and UK. Shakkan-ho displays traditional Japanese weight units like momme and kan.
For extremely large or small values, the converter automatically switches to scientific notation to keep results readable and accurate.
How the Converter Works
This tool uses standardized conversion factors based on the kilogram, the SI base unit of mass. Every unit has a precise mathematical relationship to the kilogram, and the converter applies these ratios instantly.
For example, 1 kilogram equals exactly 2.20462 pounds. When you enter a value, the tool first converts it to kilograms, then calculates the equivalent in all other units using their respective conversion factors.
The results are accurate to multiple decimal places, with automatic rounding applied for readability. For scientific or industrial applications requiring extreme precision, the converter displays up to 12 significant figures in exponential notation.
Note: This tool provides mathematical conversions only. For trade, legal, or medical purposes, always verify with certified scales and consult relevant regulations.
Common Weight Conversions (Quick Reference)
Here are some frequently needed conversions for quick reference. One kilogram equals 2.205 pounds or 35.274 ounces. One pound equals 453.592 grams or 16 ounces. One ounce equals 28.35 grams. One stone equals 14 pounds or 6.35 kilograms. One metric ton equals 2,204.6 pounds. One gram equals 5 carats, which is useful for gemstones. One grain equals 64.799 milligrams, commonly used in ammunition and medicine.
FAQ（Frequently Asked Questions）
- What’s the difference between mass and weight?
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Technically, mass measures the amount of matter (in kilograms), while weight measures gravitational force (in newtons). In everyday use, they’re treated interchangeably, and this converter handles both contexts.
- Why are there two types of tons?
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The metric ton (1,000 kg) is standard internationally. The short ton (2,000 lbs) is common in the US, while the long ton (2,240 lbs) is used in the UK. This converter includes all three.
- What are Shakkan-ho units?
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Shakkan-ho is a traditional Japanese measurement system. The momme (3.75 grams) is still used today in the pearl industry worldwide.
- How accurate is this converter?
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Conversions use internationally recognized conversion factors and are accurate to at least 6 significant figures for common units.
- Can I use this for cooking measurements?
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Absolutely. It’s perfect for converting recipe ingredients between metric and imperial units — just enter your weight and find the equivalent instantly.
More Than Just Numbers
Whether you’re adjusting a recipe, calculating shipping costs, tracking fitness progress, or working on a science project, accurate weight conversions matter.
Bookmark this page for quick access whenever you need it. And if you found this tool helpful, check out the related converters below for length, volume, and more.
