What is the weight and mass converter?
The weight and mass converter is a collection of calculators for changing one weight and mass unit into another. Convert common weight and mass units for body weight, shipping, cooking, science, and fitness tracking.
Weight and mass conversions are common for body weight, shipping labels, recipes, gym tracking, lab measurements, and comparing metric and US customary units.
Available weight and mass units
This category includes the following units:
- Kilogram (kg)
- Pound (lb)
- Gram (g)
- Ounce (oz)
- Stone (st)
- Metric Ton (t)
Common weight and mass use cases
Use this category when the same measurement appears in different unit systems, data sheets, calculators, reports, or regional conventions.
- Weight and Mass conversions help compare measurements across specifications, calculators, labels, and technical references.
- Use this category when source data and target documents use different weight and mass units.
- The dedicated conversion pages show formulas, examples, tables, related pages, and FAQ for individual unit pairs.
Professional weight and mass guidance
These notes are written for the highest-traffic weight and mass pages, where users often need more than a raw number.
Mass, weight, and everyday labels
Most consumer pages use weight language, but kilograms, grams, pounds, ounces, and stone are mass-style units in ordinary conversion workflows. Engineering contexts may distinguish mass from force, so keep that distinction in mind for loads and force calculations.
Use the right precision for the task
Body weight, parcel weight, recipe weight, and lab mass do not need the same rounding. A package near a shipping threshold may need more decimal places than a casual body-weight comparison.
Popular weight and mass units explained
These short unit notes help readers choose the right starting unit before opening a specific conversion page.
Kilogram (kg)
A kilogram is the base metric unit of mass. It is used for body weight, shipping weight, groceries, science, and international product specifications.
Browse kg conversionsPound (lb)
A pound is a US customary and imperial weight unit. It is common for body weight, food packaging, shipping labels, and fitness measurements.
Browse lbs conversionsGram (g)
A gram is a metric mass unit equal to one thousandth of a kilogram. It is common in cooking, nutrition labels, medicine, and laboratory work.
Browse grams conversionsOunce (oz)
An ounce is a US customary and imperial weight unit. It is used for small food quantities, mailing weight, recipes, and precious metals.
Browse ounces conversionsStone (st)
Stone (st) is a weight and mass unit.
Browse stone conversionsMetric Ton (t)
Metric Ton (t) is a weight and mass unit.
Browse metric-tons conversionsCommon weight and mass conversion mistakes
Most wrong answers come from mixing unit systems, rounding too early, or choosing a unit that looks similar but means something different.
- Do not mix mass units with force units in engineering contexts.
- Do not confuse ounces of weight with fluid ounces of volume.
- Do not round too early near shipping thresholds, dosage limits, product labels, or body-weight records.
Popular weight and mass conversion pages
Start with one of these common weight and mass conversions:
Browse weight and mass conversions by starting unit
Use these grouped links when you know the unit you are starting from and want to compare several destination units.
Kilogram conversions
Start with kilograms and convert to common weight and mass units.
Pound conversions
Start with pounds and convert to common weight and mass units.
Gram conversions
Start with grams and convert to common weight and mass units.
Ounce conversions
Start with ounces and convert to common weight and mass units.
Stone conversions
Start with stone and convert to common weight and mass units.
Metric Ton conversions
Start with metric tons and convert to common weight and mass units.
All weight and mass conversion pages
This complete index helps users and search engines discover every generated weight and mass conversion page.
Related categories and references
Use these links to move between neighboring converter categories, hand-written unit references, popular units, and complete site indexes.
Unit Wiki and references
Popular weight and mass units
Complete indexes and tools
How weight and mass conversion works
Most pages in this category use a conversion factor between two units. The calculator applies that factor automatically and shows the result instantly.
How to use this converter
Enter a value, choose the units, and read the converted result immediately. Each dedicated conversion page also includes a formula, examples, a conversion table, related links, and FAQ.
FAQ
Which weight and mass units are included?
This category includes kilograms, pounds, grams, ounces, stone, metric tons and related units.
Are formulas included?
Yes. Individual conversion pages include formulas, manual steps, examples, and conversion tables.
Are pounds and kilograms measuring the same thing here?
For everyday conversion pages, they are treated as comparable mass or weight units. In engineering, check whether the source means pound mass or pound force.
Which weight units are best for recipes?
Grams are usually best for precision, while ounces and pounds are common in US recipes and package labels.