Inches to Centimeters
Convert length between inches and centimeters.
1 inch = 2.54 cm exactly (definition). Edit either field — values stay in sync.
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 for product specs, height forms, sewing patterns, and school science.
In the UK and much of Europe, centimetres (and millimetres) dominate everyday measurement, while many US product labels, monitor diagonals, and older patterns still use inches. Converting carefully once — then rounding only for display — avoids the compounding error that comes from converting a rounded result back and forth.
Formulas (both directions)
- Inches → centimeters: centimeters = inches × 2.54
- Centimeters → inches: inches = centimeters ÷ 2.54
- Millimetres: 1 cm = 10 mm, so inches × 25.4 = millimeters
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 US product spec, a metric ruler, or a UK clothing size chart that lists cm.
Worked examples: inches to centimeters
| Inches | Centimeters | Typical use |
|---|---|---|
| 1 in | 2.54 cm | Definition check |
| 12 in (1 ft) | 30.48 cm | Ruler / foot length |
| 15.6 in | 39.624 cm | Laptop screen diagonal |
| 36 in | 91.44 cm | Yardstick / fabric length |
| 70 in | 177.8 cm | 5′10″ height as total inches |
Worked examples: centimeters to inches
| Centimeters | Inches (approx.) | Typical use |
|---|---|---|
| 10 cm | 3.937 in | Small craft / stationery |
| 30 cm | 11.811 in | Nearly one foot |
| 100 cm | 39.370 in | One metre |
| 152.4 cm | 60 in (5′0″) | Height forms |
| 180 cm | 70.866 in (~5′11″) | Height forms |
Feet and inches → cm (common height workflow)
- Multiply feet by 12, then add leftover inches to get total inches.
- Multiply total inches by 2.54.
- Round once for the form (often whole cm or one decimal).
Example: 5′8″ → (5 × 12) + 8 = 68 inches → 68 × 2.54 = 172.72 cm. Enter 68 in the inches field above to confirm.
Height quick reference
| Imperial height | Total inches | Centimeters |
|---|---|---|
| 5′0″ | 60 | 152.40 |
| 5′4″ | 64 | 162.56 |
| 5′6″ | 66 | 167.64 |
| 5′10″ | 70 | 177.80 |
| 6′0″ | 72 | 182.88 |
| 6′2″ | 74 | 187.96 |
When each unit is used
- Inches — US product dimensions, many monitor and TV diagonals, some sewing and craft patterns, and imperial height on older forms.
- Centimetres / millimetres — UK and EU clothing and furniture specs, school science, most European DIY, and medical height fields that expect metric.
- Mixed documents — Online shopping across regions; convert the printed number before comparing two listings.
Practical scenarios
Buying furniture across regions. A US listing shows a desk as 60″ wide. Convert once: 60 × 2.54 = 152.4 cm. Measure your alcove in centimetres (or convert the alcove to inches) and compare in one unit only. Do not convert the desk to cm, round, convert back to inches, and compare again — rounding error grows.
Clothing and body measurements. UK/EU size charts often list chest, waist, and inseam in cm. If you measured yourself in inches, convert each measurement with the exact factor, then round to the chart’s precision (often whole centimetres). For height on a metric form, convert total inches in one step as shown above.
School and lab work. Science problems usually expect metric answers. Convert imperial givens to cm or mm first, then compute. If the answer key lists inches, convert only the final result for comparison.
How to use this converter
- Type a value in Inches or in Centimeters.
- Read the paired field — it stays in sync.
- Copy the result you need; re-enter if you are chaining several measurements.
- Round only at the end for display (for example, one decimal for clothing sizes).
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 or height.
- Squaring a rounded length to get area — convert each linear dimension first, or use a dedicated area tool.
- Converting a rounded result back to the other unit repeatedly, which accumulates display error.
Decision checklist
- Do I have feet + inches? → Convert to total inches first.
- Do I need mm? → Convert to cm, then × 10 (or inches × 25.4).
- Is this area/volume? → Do not use this page alone; convert each linear edge carefully.
- Is the lumber size “nominal”? → Measure actual inches; a “2×4” is not finished 2″ × 4″.
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.
Why does my phone disagree by 0.01 cm?
Most apps round for display. Small differences usually come from rounding, not from a different definition of the inch.
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.