12 inches in cm = 30.48. Because 12 inches is exactly 1 foot, this is one of the cleanest conversions in the imperial-to-metric table. The rest of this guide covers the exact formula, a full conversion table from 1 to 36 inches, a quick mental shortcut, and the situations where you're most likely to need it.
Use the Unit Converter → to convert any length, weight, or temperature instantly — no formula needed.
12 Inches in CM: The Direct Answer (1 Foot = 30.48 cm)
12 inches = 30.48 centimeters (exact, not rounded).
This precision comes from the definition of the inch itself. Since the International Yard and Pound Agreement of 1959, adopted by the US, UK, Canada, Australia, New Zealand, and South Africa, 1 inch has been defined as exactly 2.54 centimeters (NIST, 1959). There is no rounding — 12 × 2.54 = 30.48, full stop.
Key Takeaways
The Exact Formula (Both Directions)
Inches → Centimeters
```
cm = inches × 2.54
```
Example: 12 in × 2.54 = 30.48 cm
Centimeters → Inches
```
inches = cm ÷ 2.54
```
Example: 30.48 cm ÷ 2.54 = 12.00 in ✓
Equivalently: inches = cm × 0.393701
The factor 2.54 is exact — it's a definition, not a measurement. This means any error in your conversion comes from rounding the result, never from the conversion factor itself.
Conversion Table: 1 to 36 Inches in Centimeters
| Inches | Centimeters | Notes |
|---|---|---|
| 1 | 2.54 | |
| 2 | 5.08 | |
| 3 | 7.62 | |
| 4 | 10.16 | |
| 5 | 12.70 | |
| 6 | 15.24 | Half a foot |
| 7 | 17.78 | |
| 8 | 20.32 | |
| 9 | 22.86 | |
| 10 | 25.40 | |
| 11 | 27.94 | |
| 12 | 30.48 | 1 foot |
| 13 | 33.02 | |
| 14 | 35.56 | |
| 15 | 38.10 | |
| 16 | 40.64 | |
| 17 | 43.18 | |
| 18 | 45.72 | 1.5 feet |
| 19 | 48.26 | |
| 20 | 50.80 | |
| 24 | 60.96 | 2 feet |
| 30 | 76.20 | 2.5 feet |
| 36 | 91.44 | 3 feet / 1 yard |
All values are exact (2.54 cm per inch, no intermediate rounding).
For lengths not in this table, use the Unit Converter → — it handles inches, feet, yards, meters, and centimeters in any combination.
When Does Inches-to-CM Actually Come Up?
The most common trigger is a screen size listing. In the US, tablet and monitor diagonals are advertised in inches; European retailers and international spec sheets list them in centimeters. A 12-inch tablet is 30.48 cm diagonally. A 27-inch monitor is 68.58 cm. The formula never changes: multiply inches by 2.54.
TV and monitor screen sizes. Buying an international or off-brand monitor means reading the spec in cm and checking it against a US-listed size. Knowing that 30.48 cm = 12 inches and 68.58 cm = 27 inches anchors the comparison without a converter.
Height on medical and international forms. Clinics and health apps outside the US record patient height in centimeters. Five feet = 60 inches = 152.40 cm; 5'4" = 64 inches = 162.56 cm. If you need your height in centimeters to calculate BMI, the BMI Calculator accepts feet/inches directly and handles the conversion internally.
Furniture and interior dimensions. A 12-inch shelf bracket is 30.48 cm deep. IKEA and other European retailers publish dimensions in cm; US big-box stores use inches. You need the same formula to match them.
Cooking and bakeware. A 12-inch cast iron skillet has a cooking surface of approximately 30 cm — close enough that a European recipe calling for a 28 cm pan will work in a US 12-inch pan (28 ÷ 2.54 = 11.02 inches, one size down).
Body measurements. Waist and hip circumferences measured in inches can be entered in centimeters in the Body Fat Calculator, which accepts either unit. Many body composition apps record in cm; knowing the factor means you can cross-reference without a separate tool.
Sewing and crafts. US sewing patterns list piece dimensions in inches; European patterns use cm. A pattern piece 12 inches wide is 30.48 cm — the exact conversion you need when scaling or cutting to a European spec. A standard 5/8-inch (1.59 cm) seam allowance works out to 1.6 cm in European notation. The 2.54 factor converts both directions.
The ×2.5 Mental Shortcut (and Its Limits)
For mental math, multiply inches by 2.5 instead of 2.54:
```
12 in × 2.5 = 30 cm
```
The exact answer is 30.48 cm, so the shortcut gives you 30 cm — off by 0.48 cm, a 1.6% error. For estimating the size of a TV box, a piece of furniture, or a shelf: fine. For cutting fabric to a precise pattern, measuring a window for blinds, or entering dimensions into engineering software: use 2.54.
The error compounds with longer measurements. At 12 inches it's 0.48 cm. At 36 inches (3 feet) it's 1.44 cm — enough to matter when a piece of furniture rated at 90 cm doesn't quite clear a 36-inch gap (which is actually 91.44 cm). When precision matters, the Unit Converter handles it exactly.
Frequently Asked Questions
Is 12 inches exactly 1 foot?
Yes. By definition, 1 foot = 12 inches exactly. That also means 1 foot = 30.48 cm exactly.
What is 30 cm in inches?
30 cm ÷ 2.54 = 11.81 inches. Note that 30 cm is not exactly 12 inches — it's about 11⅘ inches. The exact 12-inch equivalent is 30.48 cm. This matters when you're trying to match a 30 cm measurement to a US-sized item.
How many cm is 6 inches?
6 inches = 15.24 cm (half of 30.48). Six inches is also half a foot.
How many inches is 1 cm?
1 cm = 0.393701 inches, or about 25/64 of an inch. For mental math: 1 cm ≈ 3/8 of an inch (0.375 in — slightly short). For exact work, use 0.3937 or the Unit Converter.
Is a 12-inch ruler actually 30.48 cm?
Yes, to within manufacturing tolerance. Standard 12-inch rulers sold in the US are nominally 30.48 cm, and you can usually verify this on the reverse side of rulers that print both scales. The slight discrepancy you might see between the inch markings and the centimeter markings is printing tolerance, not a different definition.
For the 12 inches in cm conversion — or any other length, weight, or temperature — the Unit Converter → handles metric, imperial, and US customary units in one place.