Last reviewed: June 2026
How to Use the Weight Converter
What the Weight Converter Does
The Weight Converter lets you edit any supported weight field and automatically updates every other unit. Whichever box you change becomes the source—there is no separate from or to selector.
Supported Weight Units
Five metric and imperial units appear together in one grid: milligrams (mg), grams (g), kilograms (kg), ounces (oz), and pounds (lb).
How to Edit and Convert Values
Type a number in any supported unit. All other weight units refresh to match the value you entered. Tap a Common values chip (such as 1 oz, 1 lb, or 100 g) to load a starting point quickly. Use Display precision to choose Auto, 2, 3, 4, or 6 decimal places.
Precision and Rounding
Display precision controls formatted decimals, not the underlying conversion relationship. When a weight sits near a fee boundary, keep scale or factory readings in their original unit before choosing display precision.
Common Weight Conversions
- 1 pound = 16 ounces
- 1 ounce ≈ 28.3495 grams
- 1 kilogram ≈ 2.20462 pounds
- 500 grams ≈ 17.64 ounces
Net Weight, Packaged Weight, and Unit Weight
Amazon US workflows often expect ounces and pounds while overseas factories provide grams and kilograms. Before converting, confirm whether the target field expects unit weight, packaged weight, or another definition—Profit Calculator and Packaging Optimizer field labels are authoritative for each tool. Do not enter case or carton weight as a single-unit weight, and do not mix net product weight with gross packaged weight in the same field.
Shipping Weight and Dimensional Weight
Unit weight is the sellable item weight you provide for catalog and fee inputs. Shipping weight is what Amazon's fee lookup may use after size tier logic, rounding, and comparisons with dimensional weight where applicable. Dimensional weight is a volume-derived theoretical weight based on outer package dimensions. This page does not calculate it—see Calculation Methodology for divisor definitions and how xbbTools applies tier rules elsewhere.
Weighing Products for Amazon FBA
Use a scale matched to the weight range, weigh the complete sellable unit when packaged weight is required, and repeat across multiple samples while keeping raw readings in your records. Amazon inbound remeasurement can differ from supplier datasheets.
Common Mistakes
- Entering master carton weight as a single-unit weight.
- Mixing net product weight with gross packaged weight in the same field.
- Assuming converted unit weight equals Amazon shipping weight without checking tier rules.
Frequently Asked Questions
Which weight conversions are supported?
Milligrams, grams, kilograms, ounces, and pounds appear together in one grid. Enter any unit and read the others—including ounces to pounds, grams to ounces, and metric to imperial pairs.
Should I use net weight or packaged weight for Amazon FBA?
Use the weight definition required by the field you are filling—often packaged unit weight for fulfillment planning. Do not enter bare product net weight when the workflow expects the sellable unit ready for FBA.
What is the difference between unit weight and shipping weight?
Unit weight describes the sellable item input you provide. Shipping weight is what Amazon's fee lookup may use after tier rules, dimensional weight comparison, and rounding. They are related but not always identical numbers.
Why can Amazon's measured weight differ from my supplier's weight?
Packaging changes, moisture, compression, scale calibration, and remeasurement equipment can all produce differences. Convert supplier data for planning, then reconcile when Amazon publishes official weights.
How many decimal places should I keep?
Use Auto for everyday checks. Choose more decimals when documenting borderline weights, and keep unrounded scale readings in your own records.