How to Convert Between Measurement Units
Unit conversion is needed constantly in science, engineering, cooking, and daily life. Learn conversion factors for length, weight, temperature, and more.
Key Takeaways
- Most of the world uses the metric system (SI units), while the US primarily uses imperial/customary units.
- Temperature is the trickiest conversion because it involves both scaling and offset.
- Chain conversions by multiplying by conversion factors as fractions.
- Conversions introduce rounding errors.
- ## Essential Conversion Factors | Conversion | Factor | |-----------|--------| | inches → cm | × 2.
Percentage Calculator
Calculate percentages, increases, decreases, and ratios
Metric vs Imperial
Most of the world uses the metric system (SI units), while the US primarily uses imperial/customary units. Converting between them requires memorizing a few key factors or using conversion tools.
Essential Conversion Factors
| Conversion | Factor |
|---|---|
| inches → cm | × 2.54 |
| miles → km | × 1.609 |
| pounds → kg | × 0.4536 |
| gallons → liters | × 3.785 |
| °F → °C | (°F - 32) × 5/9 |
Temperature Conversion
Temperature is the trickiest conversion because it involves both scaling and offset. Celsius to Fahrenheit: multiply by 9/5 then add 32. Kelvin is Celsius + 273.15 (no scaling needed).
Dimensional Analysis
Chain conversions by multiplying by conversion factors as fractions. To convert miles per hour to meters per second: mph × 1609m/mi × 1hr/3600s. Units cancel mathematically, leaving the desired unit.
Precision and Rounding
Conversions introduce rounding errors. Keep at least 2 more significant figures than needed during calculation, then round only the final result.
Công cụ liên quan
Hướng dẫn liên quan
How to Use Scientific Notation and Number Formatting
Scientific notation makes very large and very small numbers manageable. This guide covers notation systems, significant figures, and formatting conventions used in science, engineering, and finance.
Unit Conversion Best Practices for Developers
Incorrect unit conversions have caused spacecraft crashes and medical errors. This guide covers best practices for implementing unit conversions in software, including precision handling and common pitfalls.
Percentage Calculations: Common Formulas and Pitfalls
Percentage calculations appear simple but hide common errors, especially around percentage change, percentage points, and compound percentages. This guide clarifies the math behind everyday percentage problems.
Matrix Operations: A Visual Guide for Developers
Matrices are fundamental to graphics, machine learning, and data processing. This guide explains matrix addition, multiplication, transposition, and inversion with visual examples and practical applications.
Troubleshooting Floating-Point Precision Errors
Floating-point arithmetic produces surprising results that can cause bugs in financial calculations, comparisons, and cumulative operations. This guide explains why these errors occur and how to handle them.