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Length Converter

CM ↔ Inches Converter

Instant bidirectional conversion with fraction results, visual ruler, step-by-step working, and a full reference table.

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Centimeters to Inches

Enter centimeters — get inches (decimal, fraction, feet+inches)

Quick:
Centimeters (cm)
cm
Inches (decimal)
in
Decimal precision: 4
Decimal inches
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Fraction inches
—
nearest 1/64
Feet + Inches
—
 
Millimeters
—
 
Visual scale (0 — 100 cm)
Formula: inches = cm ÷ 2.54  ·  1 cm = 0.3937 in  ·  1 in = 2.54 cm
Step-by-step calculation
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Reference & Guide

This centimeter-to-inches converter handles both directions instantly. Type in centimeters or inches, and all output formats update live: decimal inches, fractional inches (to the nearest 1/64), feet + inches, and millimeters. The step-by-step panel shows the full working so you understand every conversion, not just the answer.

What is a centimeter?

A centimeter (cm) is a unit of length in the International System of Units (SI). Centi is a Latin prefix meaning one hundredth, so one centimeter equals exactly 1/100 of a meter. The centimeter is one of the most commonly used measurements in everyday life outside the United States — for clothing sizes, body height, screen dimensions, and construction.

  • 1 cm = 1/100 meter (m)
  • 1 cm = 10 millimeters (mm)
  • 1 cm ≈ 0.3937 inches (in)
  • 1 cm ≈ 0.03281 feet (ft)
  • 100 cm = 1 meter = 3.281 feet

What is an inch?

An inch (in or ″) is a unit of length in the imperial and US customary systems. Historically, it was defined as the width of a man’s thumb. Since 1959 it has been defined as exactly 25.4 mm, which means the conversion between inches and centimeters is perfectly exact. The inch is widely used in the United States, Canada (partially), and the UK (partially) for everyday measurements.

  • 1 inch = 2.54 centimeters (cm) — exact
  • 1 inch = 25.4 millimeters (mm) — exact
  • 1 inch = 1/12 foot (ft)
  • 1 inch = 1/36 yard (yd)
  • 12 inches = 1 foot

Exact by definition: Since 1959, 1 inch = 2.54 cm exactly. This means every cm ↔ inch conversion is mathematically exact — there is no rounding in the conversion factor itself, only in the display of the result.

How to convert cm to inches

The conversion between centimeters and inches uses a single constant: 2.54. Since one inch equals exactly 2.54 centimeters, you divide centimeters by 2.54 to get inches, or multiply inches by 2.54 to get centimeters.

The formula

cm → inches:   inches = centimeters ÷ 2.54
inches → cm:   centimeters = inches × 2.54
Key fact:   1 cm = 0.393700787… inches  ·  1 in = 2.54 cm (exact)

To convert to feet + inches, first convert cm to total inches, then divide by 12. The whole number is the feet, and the remainder is the inches:

total_inches = cm ÷ 2.54
feet = floor(total_inches ÷ 12)
remaining_inches = total_inches mod 12

Worked examples

Example 1 — Convert 20 cm to inches

inches = 20 ÷ 2.54 = 7.874 inches

As feet + inches: 7.874 in ÷ 12 = 0 ft 7.874 in = 0′ 7 57⁄64″

Example 2 — Convert 50 cm to inches

inches = 50 ÷ 2.54 = 19.685 inches

As feet + inches: 19.685 ÷ 12 = 1 ft 7.685 in = 1′ 7 11⁄16″

Example 3 — Convert 170 cm to feet and inches (height)

inches = 170 ÷ 2.54 = 66.929 in

feet = floor(66.929 ÷ 12) = 5 ft

remaining = 66.929 − 60 = 6.929 in ≈ 6 15⁄16 in

Result: 5′ 6 15⁄16″ (commonly written as 5’7″)

Example 4 — Convert 5 feet 11 inches to cm (reverse)

Total inches = (5 × 12) + 11 = 71 inches

cm = 71 × 2.54 = 180.34 cm

Centimeters to inches conversion table

The fraction results below are rounded to the nearest 1/64 of an inch.

Centimeters (cm) Inches (decimal) Inches (fraction) Feet + Inches mm

Common use cases

The cm ↔ inches conversion appears in many everyday situations:

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Fashion & clothing
European clothing uses centimeters; US and UK sizing uses inches. Convert waist, chest, and inseam measurements when shopping internationally.
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Height
Most of the world records height in cm; the USA uses feet and inches. Convert 170 cm → 5’7″, or 6’0″ → 182.88 cm instantly.
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Screens & displays
TV and monitor sizes are stated in inches in most markets, but screen dimensions in cm. Convert diagonal measurements for comparison.
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Construction & DIY
Lumber and hardware specs alternate between metric and imperial by country. Convert measurements before ordering or cutting materials.
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Sports
Athletics use metric (cm for high jump, shot put distances). US sports use imperial. Convert performance data across reporting standards.
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Travel & luggage
Airline carry-on size limits are given in cm in Europe and inches in the USA. Check your bag size matches both sets of restrictions.

FAQs

How many inches is 1 cm?
1 centimeter is equal to approximately 0.3937 inches (or exactly 1/2.54 inches). To be precise: 1 cm = 0.39370078740157… inches. In practice, 0.3937 is accurate enough for almost all everyday conversions.
How many cm in 1 inch?
Exactly 2.54 centimeters. This is an exact definition set in 1959 by international agreement. So 1 inch = 2.54 cm with no rounding at all.
How do I convert cm to feet and inches?
Step 1: Divide centimeters by 2.54 to get total inches.
Step 2: Divide total inches by 12. The whole number is feet.
Step 3: The remainder (mod 12) is the inches part.

Example: 175 cm ÷ 2.54 = 68.898 in → 68.898 ÷ 12 = 5 ft 8.898 in ≈ 5′ 8 57⁄64″
What is 5 feet 7 inches in cm?
5 feet 7 inches = (5 × 12) + 7 = 67 total inches. 67 × 2.54 = 170.18 cm. So someone who is 5’7″ tall is approximately 170 cm.
How do I convert inches to a fraction?
Multiply the decimal part of the inch value by 64 (for 1/64 precision). Round to the nearest whole number. That gives you the numerator over 64, then simplify the fraction. For example: 0.874 × 64 = 55.9 ≈ 56. So 0.874 in ≈ 56/64 = 7/8 inch. This calculator does this automatically.
Is the conversion exact?
Yes — by definition. Since 1959, 1 inch = 2.54 cm exactly. There is no approximation in the conversion factor. Any rounding you see in results is purely a display choice (number of decimal places), not an error in the conversion itself.
What is 100 cm in inches?
100 cm ÷ 2.54 = 39.3701 inches (approximately). As feet + inches: 3 feet 3.37 inches (3′ 3 3⁄8″ approximately). Note that 100 cm = 1 meter.