Mass Unit Converter
Convert with explicit units, definitions and assumptions.
Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Conversion factors use the definition shown in the unit selector. US liquid and imperial measures differ. Calendar periods shown as fixed or average durations do not calculate actual calendar dates. Light-year uses a Julian year of 365.25 days. Local historical cable and league definitions outside the listed standards are not included.
Example Calculation
- Value: 1
- From: kilogram
- To: avoirdupois pound
Select two units of mass and convert using their stated factors.
Method references
Frequently asked questions
How do I use this calculator?
Enter value, from, to. The result updates automatically. Use Reset to restore the example values.
What method does it use?
output = input × input-unit factor / output-unit factor. Conversion factors use the definition shown in the unit selector. US liquid and imperial measures differ. Calendar periods shown as fixed or average durations do not calculate actual calendar dates. Light-year uses a Julian year of 365.25 days. Local historical cable and league definitions outside the listed standards are not included.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.