Inches to Centimeters

How inches ↔ centimeters conversion works

Length conversion between inches and centimeters uses an exact definition: 1 inch = 2.54 centimeters. That factor is fixed by international agreement, so the math is a simple multiply or divide — no temperature-style offsets, and no year-to-year changes. This makes inches-to-cm one of the most reliable everyday unit conversions.

Formulas

centimeters = inches × 2.54. inches = centimeters ÷ 2.54. This page keeps both fields linked: edit either side and the other updates immediately so you can start from whichever unit you already know — a U.S. product spec, a metric ruler, or a sewing pattern.

Worked examples

• 12 inches = 30.48 cm (one foot on a ruler).
• 5 feet 10 inches is 70 inches = 177.8 cm.
• 100 cm ≈ 39.37 inches.
• A 15.6-inch laptop screen diagonal ≈ 39.62 cm.

Height quick reference

• 5′0″ (60 in) = 152.4 cm
• 5′6″ (66 in) = 167.64 cm
• 6′0″ (72 in) = 182.88 cm
• 180 cm ≈ 70.87 in (about 5′11″)

When people use this

Product specs, sewing and crafts, height on medical forms, furniture dimensions, and school science problems often mix imperial and metric. Convert once carefully, then round only at the end for display (for example, to one decimal place for clothing sizes). For area or volume, convert each linear dimension first or use a dedicated area/volume tool — squaring a rounded length compounds error.

How to use it

1. Type a value in Inches or in Centimeters.
2. Read the paired field — it stays in sync.
3. Copy the result you need; re-enter if you are chaining several measurements.

Common mistakes

• Converting only feet and forgetting leftover inches (always total inches first).
• Using 2.5 as a rough factor for precision work — prefer 2.54.
• Treating screen “inches” as a single horizontal width; diagonal size is not width.

Frequently asked questions

How do I convert feet and inches to cm?

Multiply feet by 12, add inches, then multiply by 2.54. Example: 5′8″ → 68 × 2.54 = 172.72 cm.

Is a “2×4” board actually 2 inches by 4 inches?

Nominal lumber sizes differ from finished sizes. Convert the actual measured inches, not the nickname.

Millimeters?

1 cm = 10 mm, so inches × 25.4 = millimeters. Convert to cm here, then multiply by 10 if you need mm.

Limitations

Floating-point display may show many decimals; round sensibly for your use case. This converter is for length only, not area or volume. More context: metric and imperial conversions guide.