cm to inches Converter

Convert centimeters to inches instantly. Results show exact decimal inches, the nearest 1/64 fraction, and feet + inches — with a note when those two disagree.

1 in = 25.4 mm

cm to inches conversion

The international inch is defined exactly as 2.54 cm (25.4 mm). For cm to inches conversion use:

1 cm = 0.393701 in · 1 in = 2.54 cm

Step-by-step conversion (example: 100 cm)

  1. Start with the length in centimeters: 100 cm.
  2. Divide by 2.54 (exact cm per inch): 100 ÷ 2.54 = 39.3701 in.
  3. Reverse check: 39.3701 × 2.54 = 100 — the conversion round-trips cleanly.

Nearest 1/64 for 100 cm: 39 3/8 in (an approximation of the exact decimal — see “Why isn't the conversion exact?” below).

cm to inches calculator

Use the bidirectional calculator at the top of this page. Type any centimeter value, or an inch value as a decimal or a fraction (1/16, 3 1/2, 4 7/8) — decimal inches, the nearest 1/64 fraction, and feet + inches update as you type. No separate calculator engine: this page shares the same conversion math as the homepage and published cm value pages.

How to convert centimeters to fractional inches

Decimal inches are exact. Fractional inches on rulers are usually marked in 64ths. Convert cm → decimal inches, then round the fractional part to the nearest 1/64. That fraction is an approximation — the same rule the converter disclaimer uses: The inches fraction result is rounded to the nearest 1/64 fraction.

Worked example: 20 cm → nearest 1/64

  1. Divide by 2.54 (exact cm per inch): 20 ÷ 2.54 = 7.8740 in (7.874016 before display rounding).
  2. Split whole + fractional part: 7 + 0.874016.
  3. Multiply the fractional part by 64: 0.874016 × 64 = 55.94 → round to nearest integer 56 (the numerator over 64).
  4. Simplify 56/64 → 7/8.
  5. Combine with the whole inches: 7 7/8 in. That is ≈ 7.8740 in, not exact — see Why isn't the conversion exact? (fraction error here: +0.025 mm).

Tip: if you only need decimal inches, stop after step 1. Use the fraction steps when reading a tape or chart marked in 64ths.

Diagram of an inch divided into halves, quarters, eighths, and sixteenths on a measuring-tape style scale
Fractions of an inch (½, ¼, ⅛, 1/16). Our converter and chart use the finer nearest 1/64 grid on the same inch.

cm to inches chart

Full chart from shared nearest-1/64 logic (same engine as the converter). Decimal inches are exact to four places; the fraction column is the nearest 1/64 and can differ from the decimal. “Print chart” prints only these tables (or save them as a PDF from the print dialog).

0–100 cm (every 1 cm)

cminches (decimal)inches (nearest 1/64)
00.00000
10.393725/64
20.787425/32
31.18111 3/16
41.57481 37/64
51.96851 31/32
62.36222 23/64
72.75592 3/4
83.14963 5/32
93.54333 35/64
103.93703 15/16
114.33074 21/64
124.72444 23/32
135.11815 1/8
145.51185 33/64
155.90555 29/32
166.29926 19/64
176.69296 11/16
187.08667 3/32
197.48037 31/64
207.87407 7/8
218.26778 17/64
228.66148 21/32
239.05519 1/16
249.44889 29/64
259.84259 27/32
2610.236210 15/64
2710.629910 5/8
2811.023611 1/32
2911.417311 27/64
3011.811011 13/16
3112.204712 13/64
3212.598412 19/32
3312.992112 63/64
3413.385813 25/64
3513.779513 25/32
3614.173214 11/64
3714.566914 9/16
3814.960614 61/64
3915.354315 23/64
4015.748015 3/4
4116.141716 9/64
4216.535416 17/32
4316.929116 59/64
4417.322817 21/64
4517.716517 23/32
4618.110218 7/64
4718.503918 1/2
4818.897618 57/64
4919.291319 19/64
5019.685019 11/16
5120.078720 5/64
5220.472420 15/32
5320.866120 55/64
5421.259821 17/64
5521.653521 21/32
5622.047222 3/64
5722.440922 7/16
5822.834622 53/64
5923.228323 15/64
6023.622023 5/8
6124.015724 1/64
6224.409424 13/32
6324.803124 51/64
6425.196925 13/64
6525.590625 19/32
6625.984325 63/64
6726.378026 3/8
6826.771726 49/64
6927.165427 11/64
7027.559127 9/16
7127.952827 61/64
7228.346528 11/32
7328.740228 47/64
7429.133929 9/64
7529.527629 17/32
7629.921329 59/64
7730.315030 5/16
7830.708730 45/64
7931.102431 7/64
8031.496131 1/2
8131.889831 57/64
8232.283532 9/32
8332.677232 43/64
8433.070933 5/64
8533.464633 15/32
8633.858333 55/64
8734.252034 1/4
8834.645734 41/64
8935.039435 3/64
9035.433135 7/16
9135.826835 53/64
9236.220536 7/32
9336.614236 39/64
9437.007937 1/64
9537.401637 13/32
9637.795337 51/64
9738.189038 3/16
9838.582738 37/64
9938.976438 31/32
10039.370139 3/8

110–1000 cm (every 10 cm)

cminches (decimal)inches (nearest 1/64)feet + inches
11043.307143 5/163 ft 7 5/16 in
12047.244147 1/43 ft 11 1/4 in
13051.181151 3/164 ft 3 3/16 in
14055.118155 1/84 ft 7 1/8 in
15059.055159 1/164 ft 11 1/16 in
16062.992162 63/645 ft 2 63/64 in
17066.929166 59/645 ft 6 59/64 in
18070.866170 55/645 ft 10 55/64 in
19074.803174 51/646 ft 2 51/64 in
20078.740278 47/646 ft 6 47/64 in
21082.677282 43/646 ft 10 43/64 in
22086.614286 39/647 ft 2 39/64 in
23090.551290 35/647 ft 6 35/64 in
24094.488294 31/647 ft 10 31/64 in
25098.425298 27/648 ft 2 27/64 in
260102.3622102 23/648 ft 6 23/64 in
270106.2992106 19/648 ft 10 19/64 in
280110.2362110 15/649 ft 2 15/64 in
290114.1732114 11/649 ft 6 11/64 in
300118.1102118 7/649 ft 10 7/64 in
310122.0472122 3/6410 ft 2 3/64 in
320125.9843125 63/6410 ft 5 63/64 in
330129.9213129 59/6410 ft 9 59/64 in
340133.8583133 55/6411 ft 1 55/64 in
350137.7953137 51/6411 ft 5 51/64 in
360141.7323141 47/6411 ft 9 47/64 in
370145.6693145 43/6412 ft 1 43/64 in
380149.6063149 39/6412 ft 5 39/64 in
390153.5433153 35/6412 ft 9 35/64 in
400157.4803157 31/6413 ft 1 31/64 in
410161.4173161 27/6413 ft 5 27/64 in
420165.3543165 23/6413 ft 9 23/64 in
430169.2913169 19/6414 ft 1 19/64 in
440173.2283173 15/6414 ft 5 15/64 in
450177.1654177 11/6414 ft 9 11/64 in
460181.1024181 7/6415 ft 1 7/64 in
470185.0394185 3/6415 ft 5 3/64 in
480188.9764188 31/3215 ft 8 31/32 in
490192.9134192 29/3216 ft 29/32 in
500196.8504196 27/3216 ft 4 27/32 in
510200.7874200 25/3216 ft 8 25/32 in
520204.7244204 23/3217 ft 23/32 in
530208.6614208 21/3217 ft 4 21/32 in
540212.5984212 19/3217 ft 8 19/32 in
550216.5354216 17/3218 ft 17/32 in
560220.4724220 15/3218 ft 4 15/32 in
570224.4094224 13/3218 ft 8 13/32 in
580228.3465228 11/3219 ft 11/32 in
590232.2835232 9/3219 ft 4 9/32 in
600236.2205236 7/3219 ft 8 7/32 in
610240.1575240 5/3220 ft 5/32 in
620244.0945244 3/3220 ft 4 3/32 in
630248.0315248 1/3220 ft 8 1/32 in
640251.9685251 31/3220 ft 11 31/32 in
650255.9055255 29/3221 ft 3 29/32 in
660259.8425259 27/3221 ft 7 27/32 in
670263.7795263 25/3221 ft 11 25/32 in
680267.7165267 23/3222 ft 3 23/32 in
690271.6535271 21/3222 ft 7 21/32 in
700275.5906275 19/3222 ft 11 19/32 in
710279.5276279 17/3223 ft 3 17/32 in
720283.4646283 15/3223 ft 7 15/32 in
730287.4016287 13/3223 ft 11 13/32 in
740291.3386291 11/3224 ft 3 11/32 in
750295.2756295 9/3224 ft 7 9/32 in
760299.2126299 7/3224 ft 11 7/32 in
770303.1496303 5/3225 ft 3 5/32 in
780307.0866307 3/3225 ft 7 3/32 in
790311.0236311 1/3225 ft 11 1/32 in
800314.9606314 61/6426 ft 2 61/64 in
810318.8976318 57/6426 ft 6 57/64 in
820322.8346322 53/6426 ft 10 53/64 in
830326.7717326 49/6427 ft 2 49/64 in
840330.7087330 45/6427 ft 6 45/64 in
850334.6457334 41/6427 ft 10 41/64 in
860338.5827338 37/6428 ft 2 37/64 in
870342.5197342 33/6428 ft 6 33/64 in
880346.4567346 29/6428 ft 10 29/64 in
890350.3937350 25/6429 ft 2 25/64 in
900354.3307354 21/6429 ft 6 21/64 in
910358.2677358 17/6429 ft 10 17/64 in
920362.2047362 13/6430 ft 2 13/64 in
930366.1417366 9/6430 ft 6 9/64 in
940370.0787370 5/6430 ft 10 5/64 in
950374.0157374 1/6431 ft 2 1/64 in
960377.9528377 61/6431 ft 5 61/64 in
970381.8898381 57/6431 ft 9 57/64 in
980385.8268385 53/6432 ft 1 53/64 in
990389.7638389 49/6432 ft 5 49/64 in
1000393.7008393 45/6432 ft 9 45/64 in

1100–3000 cm in feet and inches (every 100 cm)

For height, doors, and panels, lengths are often spoken as feet + inches. The feet + inches column rounds the leftover inches to the nearest 1/64.

cminches (decimal)feet + inches
1100433.070936 ft 1 5/64 in
1200472.440939 ft 4 7/16 in
1300511.811042 ft 7 13/16 in
1400551.181145 ft 11 3/16 in
1500590.551249 ft 2 35/64 in
1600629.921352 ft 5 59/64 in
1700669.291355 ft 9 19/64 in
1800708.661459 ft 21/32 in
1900748.031562 ft 4 1/32 in
2000787.401665 ft 7 13/32 in
2100826.771768 ft 10 49/64 in
2200866.141772 ft 2 9/64 in
2300905.511875 ft 5 33/64 in
2400944.881978 ft 8 7/8 in
2500984.252082 ft 1/4 in
26001023.622085 ft 3 5/8 in
27001062.992188 ft 6 63/64 in
28001102.362291 ft 10 23/64 in
29001141.732395 ft 1 47/64 in
30001181.102498 ft 5 7/64 in

Why isn't the conversion exact?

Fractional inches on rulers are usually marked in 64ths. One centimeter is 0.3937 in ≈ 25.2/64 — not an integer tick — so the nearest 1/64 is always an approximation.

Ruler from 0 to 1 inch with fractional marks, showing how metric and imperial tick marks relate
0–1 inch with imperial fractional marks — useful when comparing a cm length to ruler ticks (image via Wikimedia Commons, CC BY-SA 3.0).

Example: 4 cm on a 1/64 grid

  • 4 cm = 1.5748 in exactly. Nearest 1/64: 1 37/64 in (+0.084 mm from exact).
  • 4 cm ≠ 1 in. 1 in = 2.54 cm — a difference of -1.46 cm.

Decimal inches stay exact; fractions are nearest-tick approximations — which is why the converter shows both and notes when they disagree.

cm in feet and inches

Height charts and everyday speech often round to the nearest whole inch after converting to feet + inches. That spoken form is convenient but not the same as the exact international conversion rounded to the nearest 1/64.

  • 180 cm = 70.8661 in exactly. Colloquially you may hear ≈ 5′11″ (nearest-inch rounding). This engine’s nearest 1/64 feet + inches: 5 ft 10 55/64 in — not the same as claiming 180 cm equals 5′11″ exactly.
  • 170 cm = 66.9291 in exactly. Colloquially you may hear ≈ 5′7″ (nearest-inch rounding). This engine’s nearest 1/64 feet + inches: 5 ft 6 59/64 in — not the same as claiming 170 cm equals 5′7″ exactly.
  • 160 cm = 62.9921 in exactly. Colloquially you may hear ≈ 5′3″ (nearest-inch rounding). This engine’s nearest 1/64 feet + inches: 5 ft 2 63/64 in — not the same as claiming 160 cm equals 5′3″ exactly.

Use the converter at the top for any cm value; the chart above lists feet + inches for longer metric lengths.

cm to inches in everyday objects

ISO sizes you can verify on a ruler or spec sheet (not rounded marketing claims):

  • ID-1 card (ISO/IEC 7810): 85.60 × 53.98 mm — long edge ≈ 8.56 cm ( 3.3701 in).
  • A4 paper (ISO 216): 210 × 297 mm — 21.0 × 29.7 cm ( 8.2677 × 11.6929 in).

10 cm = 3.9370 in (nearest 1/64: 3 15/16 in) — a little longer than the long edge of a standard ID-1 card (85.60 mm).

Common conversions

Published cm value pages (same converter engine as this hub).

  • mm to inches — decimal, fraction, feet + inches, and chart
  • inches to cm — type inches (decimals or fractions like 3 1/2) into the converter at the top
  • cm to mm — use the general Length Converter
  • cm to feet — the converter shows feet + inches for anything 12 in and up
  • meters to feet — use the general Length Converter
  • Length Converter — every pair of mm, cm, m, km, in, ft, yd, and mi
  • All length tools — hubs, drill bits, and published values

References

Conversion on this page uses the international inch (exactly 2.54 cm / 25.4 mm). Primary sources:

  1. NIST — SI Units: Length — states that since the 1959 yard agreement, the standard inch is exactly equivalent to 25.4 mm.
  2. Federal Register Notice 59-5442 (PDF) — July 1, 1959 announcement of the international yard and the inch = 25.4 mm exactly.
  3. NIST Guide to the SI, Appendix B — conversion factors based on the international foot/inch (1 in = 0.0254 m exactly).

FAQ

See also: 20 cm to inches and 15 cm to inches.

  • How many cm means 1 inch?

    2.54 cm — exactly, by definition. Since 1959 the international inch is defined as exactly 25.4 mm (2.54 cm).

  • Is 4 cm 1 inch?

    No. 4 cm = 1.5748 in, while 1 inch = 2.54 cm — a difference of 1.46 cm.

  • Is 3 cm the same as 1 inch?

    No. 3 cm = 1.1811 in — about 0.1811 in more than a full inch (1 inch = 2.54 cm).

  • What does 10 cm look like in inches?

    10 cm = 3.9370 in (nearest 1/64: 3 15/16 in). That is a little longer than the long edge of a standard ID-1 credit card (85.60 mm).