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Weight Converter

Convert kg to lbs, grams to ounces, stone to kg & 50+ weight units instantly. Used by fitness enthusiasts, chefs & medical pros. Free, no sign-up, exact SI conversion factors.

Last revised 9 September 2026

By Team GlobalCalqulate · About our editorial standards

Weight Conversion

Value

Enter the weight value to convert.

From Unit

Select the unit you want to convert from.

To Unit

Select the unit you want to convert to.

Decimal Places

Number of decimal places for the result (max 15).

Disclaimer: In everyday speech 'weight' usually means mass (kg, lb) rather than the scientific sense of weight as a gravitational force (measured in newtons) — this converter uses the everyday, mass-based meaning, like a kitchen or bathroom scale. Conversion factors between mass units (e.g. 1 kg = 2.20462262185 lbs) are exact by definition; any imprecision in a real-world reading comes from your scale, not from this conversion. Full disclaimer.

Sources & methodology

Formula:: Two-step conversion through a base unit
Reference:: Bureau International des Poids et Mesures (BIPM)
Content last updated:: September 2026
Scheduled re-verification:: September 2027

Calculation type: Exact calculation. Figures are taken from Bureau International des Poids et Mesures (BIPM) and National Institute of Standards and Technology (NIST) and Hong Kong e-Legislation — see sources below.

Formula & methodology

Formula used

Two-step conversion through a base unit

value_out = (value_in × factor_in→the kilogram) ÷ factor_out→the kilogram

Every mass unit is defined as a multiple of the kilogram. A conversion goes in to the kilogram and back out again, so one factor per unit covers every possible pair rather than needing a factor for each combination.

Variable definitions

Symbol	Meaning	Unit
factor	Conversion factor. how many kilograms one unit represents	kg

Step-by-step calculation

1. Choose the unit you have
The value is converted to kilograms first.
2. Choose the unit you want
Kilograms are converted out to the target unit.

Limitations

This converts MASS, not weight in the physical sense. Weight is a force and depends on local gravity; mass does not.
The ton is ambiguous: a metric tonne is 1000 kg, a US short ton about 907 kg, and an Imperial long ton about 1016 kg.
The conversion factors are exact by definition, not measured, so the only error in a result is the rounding you choose for display.

This page is educational. It converts between units using the defined or standard factors shown above, so the arithmetic is exact to the precision displayed — but a converted value is only as good as the measurement behind it, and some units are defined only under stated conditions. Where a conversion is safety-critical or contractual, check it against the governing standard rather than relying on this page.

Sources & references

The International System of Units (SI Brochure, 9th edition) — Bureau International des Poids et Mesures (BIPM)
NIST Special Publication 811: Guide for the Use of the International System of Units — Appendix B.6, exact conversion factors — National Institute of Standards and Technology (NIST)
Weights and Measures Ordinance (Cap. 68), Schedule 1 — legal values of the catty, tael and mace — Hong Kong e-Legislation

Verified against internationally recognized measurement standards (BIPM SI Brochure, NIST, and other applicable standards); see the sources above for the specific documents used. Every factor on this page is exact by definition rather than an empirical measurement, except where the page says otherwise — so results are limited only by the display rounding you choose. Standards review: August 2026. Traditional units (catty, tael, mace, tola, baht) are national or trade definitions, not international standards, and are labelled as such.

Help & FAQs

Frequently Asked Questions

Clear answers to common questions to help you use this calculator confidently.

What is mass conversion?

Tap to view the answer

Mass conversion converts weight measurements between different units like kilograms, pounds, ounces, and more.

How many mass units are supported?

Tap to view the answer

The mass converter supports 20+ units including kg, g, mg, lb, oz, stone, tons, and traditional units.

How accurate are the conversions?

Tap to view the answer

Conversions use standard international factors and are accurate to your chosen decimal places.

Need more help? Contact support or email globalcalqulate@gmail.com

We typically reply within 24–48 hours.

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From	To	Conversion
1 kg	2.2046 lbs	2.2046
1 lb	0.4536 kg	0.4536
1 lb	16 oz	16
1 oz	28.35 g	28.35
1 stone (UK)	14 lbs	6.350 kg
1 metric ton	1,000 kg	1000
1 metric ton	2,204.6 lbs	2204.6
1 US ton	2,000 lbs	907.2 kg
1 g	0.0353 oz	0.0353
5 kg	11.023 lbs	11.023
10 kg	22.046 lbs	22.046
50 kg	110.23 lbs	110.23
100 kg	220.46 lbs	220.46

From	To	Conversion
1 kg	2.2046 lbs	2.2046
1 lb	0.4536 kg	0.4536
1 lb	16 oz	16
1 oz	28.35 g	28.35
1 stone (UK)	14 lbs	6.350 kg
1 metric ton	1,000 kg	1000
1 metric ton	2,204.6 lbs	2204.6
1 US ton	2,000 lbs	907.2 kg
1 g	0.0353 oz	0.0353
5 kg	11.023 lbs	11.023
10 kg	22.046 lbs	22.046
50 kg	110.23 lbs	110.23
100 kg	220.46 lbs	220.46

Calculator inputs

Weight Conversion

Your results

Sources & methodology

Formula & methodology

Formula used

Two-step conversion through a base unit

Variable definitions

Step-by-step calculation

Limitations

Sources & references

What is mass conversion?

How many mass units are supported?

How accurate are the conversions?

Related calculators

More converters

Calculator inputs

Weight Conversion

Your results

Sources & methodology

How to Use This Calculator

Example: Convert 70 kg to lbs

Common Weight & Mass Conversions

Understanding Your Results

Key Tips

Understanding Weight Units

What is Weight?

Metric vs Imperial

Traditional Units

Formula & methodology

Formula used

Two-step conversion through a base unit

Variable definitions

Step-by-step calculation

Limitations

Sources & references

How to Use This Calculator

Example: Convert 70 kg to lbs

Common Weight & Mass Conversions

Understanding Your Results

Key Tips

Understanding Weight Units

What is Weight?

Metric vs Imperial

Traditional Units