Inches are the building block of American measurements—from your phone screen to your kitchen countertop. But when you're working on international projects or shopping online, centimeters become essential. Here's everything you need to know about converting between these two units.
The Conversion Formula
The relationship between inches and centimeters is simple and exact.
Inches to Centimeters:
cm = in × 2.54
Centimeters to Inches:
in = cm ÷ 2.54
Common Length Conversions
| Inches (in) | Centimeters (cm) |
|---|---|
| 1 | 2.54 |
| 6 | 15.24 |
| 12 (1 foot) | 30.48 |
| 36 (1 yard) | 91.44 |
| 100 | 254 |
Everyday Uses for Inches
Technology
Screen sizes are always measured diagonally in inches:
- Smartphone: 6-7 inches
- Tablet: 10-12 inches
- Laptop: 13-17 inches
- TV: 55-75 inches
DIY and Home Improvement
American tools and building materials use inches:
- Standard ruler: 12 inches (1 foot)
- Tape measure: 25-50 feet
- Common bolt sizes: 1/4", 3/8", 1/2"
- Lumber: 2x4, 2x6 (nominal inches)
Fashion
Clothing sizes often reference inches for measurements:
- Waist size: 28"-40" for men
- Jeans inseam: 30"-34"
- Shoe size: US sizes correlate with inches
Converting for Online Shopping
Many international retailers list sizes in centimeters. Here's how to convert:
- Find your measurement in inches (e.g., waist: 32")
- Multiply by 2.54 (32 × 2.54 = 81.28 cm)
- Compare with international size charts
Quick Tips
- Memorize key points: 1 inch = 2.54 cm, 1 foot = 30.48 cm
- Approximation: For quick estimates, multiply inches by 2.5
- Use our converter: For precise results, use UnitFig's length converter
Related Tools
FAQ
Why do Americans use inches?
Inches have been used in English-speaking countries since the 7th century. The US continued using the British imperial system after independence, and inches remain the standard for everyday measurements.
Are US inches different from UK inches?
No, both countries use the international inch, which is defined as exactly 2.54 centimeters.
What's the difference between inches and feet?
1 foot equals 12 inches. Feet are used for larger measurements like room dimensions, while inches are used for smaller, more precise measurements.