Centimetres to inches
The default pair — a division by exactly 2.54.
Input
10 cm → inchesOutput
3.937008 in (10 ÷ 2.54)Length Converter
Convert between mm, cm, m, km, inches, feet, yards, and miles with exact factors, precision control, a live all-units grid, and a reference table.
- Free public tool
- No sign-up for this tool
- Processing clearly labeled
- Instant results
Content last reviewed
10 centimeters equals
3.937008in
1 cm = 0.393701 in
Decimals
All units at a glance
Centimeters → Inches reference
| Centimeters (cm) | Inches (in) |
|---|---|
| 1 | 0.393701 |
| 2 | 0.787402 |
| 5 | 1.968504 |
| 10 | 3.937008 |
| 25 | 9.84252 |
| 50 | 19.685039 |
| 100 | 39.370079 |
The formula
Every length is first converted to meters(the SI base unit), then to your target unit. The factors are exact by definition: 1 inch = 2.54 cm, 1 foot = 0.3048 m, 1 mile = 1609.344 m. So cm → inches is simply cm ÷ 2.54, and m → feet is m × 3.28084.
Quick Start
Type the length
Enter the amount and pick the unit it is in.
Pick the target — or don't
Choose a To unit for the headline result, or read any unit from the live grid below.
Tune and copy
Swap direction, set decimal precision, and copy the result or any grid card.
Examples
A height, both ways at once
The grid answers the feet and inches variants together.
Input
173 cmOutput
68.11 inches · 5.6759 feet (about 5′8″) — read straight from the gridAbout the Length Converter
Length is the conversion everyone needs and nobody remembers the factor for: a height in feet and inches on an American form, curtains sized in centimetres, a running plan in kilometres, furniture listed in millimetres. This converter turns any length into every other unit the moment you type.
It covers the eight units of real life — millimetres, centimetres, metres, and kilometres on the metric side; inches, feet, yards, and miles on the imperial side — and shows them all at once, so "173 cm in feet" and "173 cm in inches" arrive together. A swap button reverses the From/To pair, decimal-precision controls round the headline result from whole numbers to six places (with a scientific-notation toggle for extremes), every grid card copies on click, and a quick-reference table lists common values for your current pair.
The factors are exact rather than approximate: by international definition one inch is precisely 2.54 cm, which fixes the whole imperial-metric relationship — a foot is 0.3048 m, a yard 0.9144 m, a mile 1,609.344 m. The formula panel shows the working, so the tool doubles as the reference you stop needing.
How to Use Length Converter
Type the length into the amount box.
Choose the From unit — the unit your number is currently in.
Read the headline result in the To unit, or take any conversion from the all-units grid, which updates live.
Use swap to reverse the pair, the decimals control (Auto
/0/2/4/6) and scientific notation toggle to shape the output, and copy on the result or any grid card.Check the quick-reference table for a run of common values in your current pair.
Key Features
Eight everyday units
mm, cm, m, km, inches, feet, yards, and miles — the set forms, listings, and workouts actually use.
Exact definitional factors
1 inch = 2.54 cm exactly, and everything that follows from it — no approximations to drift.
All units at once
The full grid converts live alongside the headline pair, each card copyable with a click.
Precision and notation control
Round to 0–6 decimals or Auto, with scientific notation for extreme values.
Reference table and formula panel
Common values for the current pair, plus the working shown so the math is checkable.
When to Use Length Converter
Heights on forms
Convert between centimetres and feet-and-inches for applications and profiles.
Buying furniture online
Turn listing centimetres or millimetres into inches before ordering.
Running and cycling distances
Read miles when the app tracks kilometres, and vice versa.
International product specs
Resolve mixed metric and imperial dimensions on the same sheet.
How It Works
Every length is first converted to metres — the SI base — by multiplying by the From unit's exact factor, then divided by the To unit's factor. Because the imperial units are defined in metric terms (inch = 0.0254 m by international agreement), the factors are exact and the two-step conversion introduces no error; rounding happens only in the display, at the precision you choose. The grid computes every unit from the same base value, which keeps all cells mutually consistent.
Supported Formats and Options
Options
From / To units with swap
Any pair of the eight units; one click reverses direction.
Decimals
Auto, 0, 2, 4, or 6 places — Auto adapts to the value's magnitude.
Scientific notation
A toggle for very large or small results.
Copy and reset
Copy the headline result or any grid card; reset restores defaults.
Common Errors and Troubleshooting
Common errors
Reading 5.9 feet as 5′9″
Decimal feet are not feet-and-inches: 5.9 ft is 5 ft 10.8 in, because a foot has 12 inches. Convert heights via inches (5′9″ = 69 in) to stay safe.
Rounding too early in multi-step work
Convert once at full precision and round the final answer — stacking pre-rounded values drifts. The precision control exists for exactly this.
Troubleshooting guide
Conversions that survive the tape measure
- Heights: go through inches. Feet-and-inches notation trips the decimal trap; total inches convert cleanly in both directions.
- Cutting and ordering: use 4–6 decimals while working and round only the figure you act on — a millimetre lost to rounding is real when it is a shelf.
- Mental estimates: 1 inch ≈ 2.5 cm and 1 foot ≈ 30 cm are fine for intuition; the exact result is what goes on the order form.
- Extreme values: flip on scientific notation rather than counting zeroes.
Limitations and Important Notes
The unit set is the everyday eight — surveying and marine units (chains, fathoms, nautical miles) are out of scope, as are feet-and-inches composite inputs (enter total inches instead). Precision is display-side only, up to six decimals or scientific notation.
Privacy and Data Processing
All conversion is local arithmetic in your browser; nothing is transmitted or saved.
Tips and Best Practices
Practical tips
Convert heights through total inches to avoid the decimal-feet trap.
Keep full precision through intermediate steps; round only the final figure.
Use the reference table to sanity-check magnitudes at a glance.
Copy from the grid card rather than retyping — transcription is where errors creep in.
Remember the factors are exact: cm → inches is precisely ÷ 2.54.
Best practices
Measured once, converted right
Decide the working unit first: pick whichever unit the final action happens in — the unit on the order form, the saw guide, the race plan — and convert everything into it once. Projects that mix units mid-stream are where the classic unit-mix-up failures live.
Write converted values with their unit every time. "172.5" is a bug waiting to happen; "172.5 cm" survives being read next week. The copy buttons include the number; you supply the label.
Technical Details
Conversion runs through a metre base with exact definitional factors (in = 0.0254, ft = 0.3048, yd = 0.9144, mi = 1609.344). Display formatting supports auto precision (six significant decimals with scientific fallback beyond 1e15/below 1e-6), fixed 0–6 decimals, and exponential notation; copy payloads are unformatted plain numbers. Client-side throughout.
Who Is This For?
Online shoppers decoding listings, travellers and expats living between systems, runners translating race distances, DIYers matching plans to tape measures, and students after exact factors with the working shown.
Frequently Asked Questions
How do I convert cm to inches?
Divide by 2.54 — one inch is defined as exactly 2.54 cm, so 30 cm ÷ 2.54 = 11.81 in. Type the value, pick Centimeters → Inches, and the division is done at full precision.
How do I convert a height like 5′9″ to centimetres?
Turn it into total inches first — 5′9″ is 69 inches — then convert: 69 × 2.54 = 175.26 cm. Going through inches avoids misreading decimal feet as feet-and-inches.
Are the conversion factors exact or rounded?
Exact by international definition: the inch is precisely 0.0254 m, which fixes the foot, yard, and mile too. Rounding only occurs in the display, at the precision you select.
Can I see all units at the same time?
Yes — the grid below the headline result converts every unit simultaneously, and each card copies its value on click.
How many decimals should I use?
Auto or 0–2 for everyday reading; 4–6 for engineering and woodworking, where the sixth decimal of an inch is real. Set it once with the precision control.