Centimetres (cm)
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Equivalent length
Accurate length conversion between inches, centimetres, millimetres, feet, and metres
Convert inches to centimetres instantly with precise calculations. Includes bidirectional conversion and a complete multi-unit length breakdown for construction, textiles, design, and everyday use in 2026.
Professional length conversion for construction, DIY, sewing, screen sizes, and product dimensions
Convert inches to centimetres using the exact international definition: 1 inch = 2.54 centimetres. This value is fixed by international agreement, so every result from this converter is mathematically precise whether you are converting fractions of an inch or very large dimensions.
Switch seamlessly between inches to centimetres and centimetres to inches. View equivalent values at the same time in millimetres, feet, and metres — giving you a complete picture across metric and imperial units with a single entry.
Ideal for builders, engineers, designers, online shoppers, students, and anyone reading measurements in one system while working in the other. Perfect for screen sizes, furniture dimensions, clothing specifications, DIY projects, and science experiments in 2026.
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The international inch is defined as exactly 25.4 millimetres, which equals 2.54 centimetres. This exact definition has been in place since 1959 and links imperial measurements directly to the metric system. Because of this, converting between inches and centimetres is simple: multiply inches by 2.54 to get centimetres, and divide centimetres by 2.54 to get inches.
This relationship is used worldwide for screen sizes (like a 15.6 inch laptop or a 55 inch TV), clothing and shoe sizes, construction dimensions in North America and the UK, and many industrial standards. Understanding the conversion allows you to compare products and drawings accurately between metric and imperial specifications.
All factors here are exact by definition, so there is no rounding error introduced by the conversion itself.
12 in × 2.54 = 30.48 cm
A standard foot-long ruler is 12 inches, which equals exactly 30.48 centimetres. Similarly, 1 inch equals 2.54 cm, so 10 inches equals 25.4 cm and 40 inches equals 101.6 cm.
Because 1 inch equals 2.54 cm exactly, multiplying by 2.54 gives you a quick mental estimate for most common product sizes.
This table shows common inch values with their equivalent centimetres and millimetres, useful for construction, design, and everyday product sizing.
| Inches (in) | Centimetres (cm) | Millimetres (mm) | Feet (ft) | Common Reference |
|---|---|---|---|---|
| 1 in | 2.54 cm | 25.4 mm | 0.0833 ft | Thumb width / small part |
| 2 in | 5.08 cm | 50.8 mm | 0.1667 ft | Small pipe / box height |
| 4 in | 10.16 cm | 101.6 mm | 0.3333 ft | Small book width |
| 6 in | 15.24 cm | 152.4 mm | 0.5 ft | Half a foot / ruler |
| 12 in ★ | 30.48 cm | 304.8 mm | 1 ft | Standard foot ruler |
| 15.6 in | 39.62 cm | 396.2 mm | 1.30 ft | Laptop screen (typical) |
| 24 in | 60.96 cm | 609.6 mm | 2 ft | Small TV / monitor |
| 32 in | 81.28 cm | 812.8 mm | 2.67 ft | Medium TV |
| 40 in | 101.6 cm | 1,016 mm | 3.33 ft | Large monitor / TV |
| 43 in | 109.22 cm | 1,092.2 mm | 3.58 ft | Popular TV size |
| 55 in | 139.7 cm | 1,397 mm | 4.58 ft | Large living-room TV |
| 65 in | 165.1 cm | 1,651 mm | 5.42 ft | Very large TV |
| 72 in | 182.88 cm | 1,828.8 mm | 6 ft | Tall person / doorway approx. |
The international inch was standardised in 1959 as exactly 25.4 millimetres. Prior to that, slightly different values existed in various countries. The definition ties the inch exactly to the metric system, making conversions precise and consistent across engineering, manufacturing, and trade.
Inches are widely used in North America and the UK for timber sizes, pipe diameters, screw lengths, and drill bits. Converting those inches into centimetres and millimetres is vital when ordering materials or reading plans in metric-based countries.
Clothing patterns, body measurements, and fabric widths often use inches, especially in US and UK materials. Knowing that 1 inch = 2.54 cm helps you translate bust, waist, and hip sizes into centimetres accurately when shopping or tailoring.
Screen diagonals for phones, tablets, laptops, monitors, and TVs are almost always quoted in inches. Converting those into centimetres lets you visualise how much space a display will take up on your desk, wall, or in a bag.
Any in → cm: Multiply by 2.54 | e.g., 10 in × 2.54 = 25.4 cm
Any cm → in: Divide by 2.54 | e.g., 30 cm ÷ 2.54 ≈ 11.81 in
Any in → mm: Multiply by 25.4 | e.g., 2 in × 25.4 = 50.8 mm
Because many online listings mix inches and centimetres, always check the unit before ordering furniture, screens, or clothing. A 40 cm monitor is much smaller than a 40 inch one. Using a converter avoids expensive mistakes when shopping or planning projects.
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