12 Inches to Centimeters: 12 in = 30.48 cm

12 Inches to Centimeters

12 inches to cm: 12 inches equals 30.48 centimeters. That is exactly one foot, and the figure is exact because an inch is defined as 2.54 cm. Twelve inches is a size you meet in rulers, tiles, pizzas and pans.

For background on the unit itself, see the inch entry on Wikipedia.

The Inches to Centimeters Formula

centimeters = inches × 2.54

12 × 2.54 = 30.48 cm

Since a foot is 12 inches, the same figure appears in the definition of the foot: exactly 30.48 cm.

Table: 6 to 24 Inches in Centimeters

12 Inches vs 30 cm

A 12-inch ruler is 30.48 cm, while a metric ruler is 30 cm. The difference is 4.8 mm, which does not matter for schoolwork but does matter for accurate cutting and fitting. If you switch between the two on one job, your measurements will drift by nearly half a centimeter for every foot of length.

Where You See 12 Inches

• Floor tiles: Square tiles are often 12 by 12 inches (30.5 cm), while metric tiles are 30 by 30 cm. The two are nearly interchangeable but not identical, which affects grout lines on large floors.
• Pizza: A 12-inch pizza is 30.5 cm across.
• Vinyl records: An LP is 12 inches wide.
• Rulers and yardsticks: The standard ruler is one foot long.

12 inches to cm for Tiling and Flooring

When you plan a floor with 12-inch tiles, convert the room to inches or feet rather than centimeters, so the tiles fit in whole units. A room 3.66 m wide is 144 inches, which takes exactly 12 tiles. If you mix metric and imperial tiles, the 4.8 mm difference per tile adds up to nearly 6 cm over a dozen tiles, which is enough to show.

Using 12 inches to cm in Crafts

Patterns and sewing guides often mix units. When you convert 12 inches to cm, use 30.48 rather than 30, and mark the fabric with a ruler that uses the same units as the instructions. A 0.48 cm error is small, but it repeats every foot. On a shelf built from three 12-inch boards, mixing 30 cm and 30.48 cm boards leaves a gap of nearly 1.5 cm, enough to rock a plate or a book. If you are unsure which unit a supplier uses, check the product label and measure a sample board before you cut anything else.

Because a foot is 12 inches, every multiple of 12 inches is a multiple of 30.48 cm: 24 inches is 60.96 cm, 36 inches is 91.44 cm and 48 inches is 121.92 cm. So 12 inches to cm is the base unit for converting any length that is given in feet.

A Quick Mental Method

Multiply inches by 2.5, then add about 1.6%. 12 × 2.5 = 30, and adding 1.6% gives 30.48, exactly the true answer.

Converting Back and Related Guides

To go back, divide centimeters by 2.54. For related pages, see 30 cm in inches, 10 inches in centimeters and the foot.

Frequently Asked Questions

How many cm is 12 inches?

12 inches is 30.48 cm.

How many mm is 12 inches?

12 inches is 304.8 millimeters.

Is 12 inches the same as 30 cm?

Nearly. 12 inches is 30.48 cm, which is 4.8 mm longer than 30 cm.

How many feet is 12 inches?

12 inches is exactly 1 foot.