Weight Converter
Convert weights across kilograms, pounds, ounces, grams, and stones.
Accurately converting weight units is a crucial task for mailing packages, scaling cooking recipes, checking airline baggage limits, and monitoring personal fitness progress. While the United States uses the Imperial system (ounces and pounds), the metric system (grams and kilograms) is the standard for sciences, manufacturing, and global trade. The Weight Converter helps you translate between these standard systems instantly.
Using incorrect weight conversions can result in postage surcharge penalties, failed baking recipes, or incorrect medical dosages. This calculator utilizes verified conversion constants, allowing you to convert ounces, pounds, grams, and kilograms client-side with absolute security and accuracy.
Weight Converter
Convert weight metrics between kilograms, pounds, grams, ounces, and stones instantly.
Conversion Table
Conversions to all other weight units are listed below.
Enter a weight value and unit, then click Convert.
How to Use the Weight Converter
To perform a conversion, select your starting unit (ounces, pounds, grams, or kilograms) and enter the value. Next, choose your target unit. The converter calculates the equivalent weight dynamically in real-time.
Practical Use Cases:
- International Parcel Shipping: Correctly calculating weights for USPS, FedEx, or DHL customs declarations requiring kilograms rather than pounds.
- Culinary and Baking: Adjusting gourmet recipes from European websites where ingredients are listed in grams instead of ounces.
- Baggage Allowances: Verifying that suitcases do not exceed standard airline luggage limits (e.g., 50 lbs, which translates to 22.68 kg).
Below is a reference table showing common weight conversions across standard US and metric systems:
| Source Weight | Target Weight | Common Use Case |
|---|---|---|
| 1.0 ounce (oz) | 28.35 grams (g) | Letter weight baseline |
| 100.0 grams (g) | 3.53 ounces (oz) | Standard spice container size |
| 16.0 ounces (oz) | 453.59 grams (g) or 1.0 lb | Standard pack of coffee beans |
| 500.0 grams (g) | 1.102 pounds (lbs) | European grocery pack of pasta |
| 1.0 pound (lb) | 0.4536 kilograms (kg) | Standard grocery loaf of bread |
| 2.2046 pounds (lbs) | 1.0 kilogram (kg) | Standard international parcel weight unit |
| 5.0 pounds (lbs) | 2.268 kilograms (kg) | Standard bag of US sugar or flour |
| 14.0 pounds (lbs) | 1.0 stone (st) or 6.35 kg | UK bodyweight measurement unit |
Formula & Calculation Logic
Weight conversions utilize standard physical constants defined internationally. The standard pound (avoirdupois) is defined as exactly 453.59237 grams.
1 pound (lb) = 0.45359237 kilograms (kg)
1 ounce (oz) = 28.349523125 grams (g)
Our tool handles all nested conversions automatically. To convert pounds to ounces, we multiply by 16. To convert kilograms to grams, we multiply by 1,000.
Real Example Calculation
Let's look at three practical US examples for weight conversions:
Example 1 (Baking Recipe): A recipe calls for 250 grams of sugar, but your kitchen scale only measures in ounces:
250 grams / 28.3495 = 8.82 ounces
You should measure out approximately 8.8 oz of sugar.
Example 2 (Mailing Package): You are mailing a box that weighs 8 pounds and 12 ounces (8.75 lbs). The postal customs form requires the weight in kilograms:
8.75 pounds × 0.45359 = 3.97 kilograms
The customs declaration form should list the package weight as 3.97 kg.
Example 3 (Gym Weight): You want to know the weight of a 45-pound plate in kilograms to compare it with metric weights:
45 pounds × 0.45359 = 20.41 kilograms
A standard 45-pound plate is approximately equal to 20.41 kg.
Frequently Asked Questions
How many ounces are in a pound?
There are exactly 16 avoirdupois ounces in one standard US pound. This is a standard measure used in US commerce.
What is the difference between dry ounces and fluid ounces?
Dry ounces (oz) measure weight, whereas fluid ounces (fl oz) measure volume. This weight converter deals strictly with dry weight ounces.
How do I convert kilograms to pounds?
To convert kilograms to pounds, multiply the kilogram value by 2.20462. For example, 10 kg equals 22.05 lbs.
How many grams are in an ounce?
There are approximately 28.35 grams in one standard dry ounce. The exact value is 28.3495 grams.
Why is the metric system preferred in sciences for weight?
The metric system uses base-10 scaling (micrograms, milligrams, grams, kilograms), which makes scaling and data analysis mathematically consistent compared to standard US divisions.
Can I convert UK stone units using this converter?
Yes, you can input stone values by converting them to pounds first (1 stone = 14 pounds) and running the calculation.
Does this weight calculator save my package weight records?
No. All calculation logic runs locally on your browser. Your weights, names, and inputs are never uploaded to any remote server, ensuring complete data security.
How do I convert milligrams to grams?
There are 1,000 milligrams in a single gram. Divide the milligram value by 1,000 to convert to grams. This is standard metric conversion.
How many grams are in a standard US pound?
There are exactly 453.59237 grams in a standard US pound. For basic kitchen measurements, this is commonly rounded to 454 grams.
What is the difference between net weight and gross weight?
Net weight refers to the weight of the product itself, excluding its packaging. Gross weight refers to the total weight of both the product and its packaging containers.