FREE LENGTH CONVERTERS AND SIZE GUIDES

Length converters that show how big it really is

Convert the measurement. See the fraction. Understand the size. Every page gives the exact answer first, then draws it to scale next to real objects.

mm to inchescm to inchesSize guides

8 mm ≈ 5/16″

Slightly more than 5/16″ (by 0.06 mm) · ≈ 0.315 in

mm
Inches
≈ 0.315 in
Nearest 1/16″
5/16″ 8 mm is 0.06 mm longer
Nearest 1/32″
5/16″ 8 mm is 0.06 mm longer
Nearest 1/64″
5/16″ 8 mm is 0.06 mm longer
024681012mm01/161/83/161/45/163/87/161/2in8 mm≈ 5/16″
Enlarged view, not actual size. Top scale: millimeters. Bottom scale: inches.

20 cm ≈ 7 7/8″

Slightly less than 7 7/8″ (by 0.03 mm) · ≈ 7.874 in

cm
Inches
≈ 7.874 in
Nearest 1/16″
7 7/8″ 20 cm is 0.03 mm shorter
Nearest 1/32″
7 7/8″ 20 cm is 0.03 mm shorter
Nearest 1/64″
7 7/8″ 20 cm is 0.03 mm shorter
0510152025cm01234567891011in20 cm≈ 7 7/8″
Scaled-down view, not actual size. Top scale: centimeters. Bottom scale: inches.

15 ft = 4.572 m

Exact, because 1 foot is defined as exactly 0.3048 m

ft
Meters
= 4.572 m

Length converters

mm to inches

Full chart with fractions.

Printable PDF
4 mm5 mm6 mm8 mm10 mm12 mm16 mm20 mm30 mm

cm to inches

Full chart from 1 to 100 cm, with inch fractions.

Printable PDF
15 cm17 cm18 cm20 cm25 cm30 cm40 cm50 cm70 cm

FEATURED GUIDE

How long is 400 meters?

About 1,312 feet or 0.2485 miles, and exactly one lap of a running track. See it next to the Eiffel Tower, the Empire State Building and the Brooklyn Bridge.

Read the guide

400 m drawn to scale
400 mtrack lap400 yards= 365.76 mEiffel Towerheight ≈ 330 mEmpire State Buildingheight to tip ≈ 443.2 mBrooklyn Bridgemain span ≈ 486.3 m

Size guides, drawn to scale

Each guide shows the length next to objects whose sizes come from a rule or published specification.

FEETHow long is 75 feet?= 22.86 m, next to real objectsFEETHow long is 60 feet?= 18.288 mFEETHow long is 15 feet?= 4.572 m, the same as a 5-yard penaltyMETERSHow long is 5 meters?≈ 16.4 ft, two swimming lanes wideMETERSHow long is 1 meter?≈ 3.28 ft, a little longer than a yardstickINCHESHow long is 7 inches?= 17.78 cm

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Popular conversions

Millimeters to inches

MM6 mm to inches≈ 15/64″MM8 mm to inches≈ 5/16″MM10 mm to inches≈ 25/64″MM16 mm to inches≈ 5/8″MM20 mm to inches≈ 25/32″

Centimeters to inches

CM20 cm to inches≈ 7 7/8″CM30 cm to inches≈ 11 13/16″CM50 cm to inches≈ 19 11/16″CM70 cm to inches≈ 27 9/16″

Feet and meters

FEET60 feet in meters= 18.288 mMETERS10 meters in feet≈ 32.81 ftMETERS1 meter in feet≈ 3.28 ft

How to convert a length

  1. Type the size. Use the converter above, or open the page for your exact size, such as 8 mm or 20 cm.
  2. Read the answer and the fraction. Each page shows the decimal, the nearest inch fraction (for example 5/16″) and whether the true value is slightly more or slightly less.
  3. Check it against real things. Every size guide is drawn to scale next to objects whose sizes come from a rule or a published specification.

Where these sizes come up

Drill bits, bolts and hardwareParts are often labelled in millimeters while tools and fittings use inch fractions. Check 8 mm, 10 mm or 12 mm.
Frames, furniture and shelvesSizes are listed in centimeters in some shops and inches in others. See 30 cm, 40 cm or 50 cm.
Phones, laptops and luggageScreen and bag sizes mix units. Try 15 cm or 18 cm and see the size on a ruler.
Rooms, yards and distancesPicture a length before you buy or build: 15 feet, 5 meters or 60 feet.

Checked, free, no sign-up

1 inch = exactly 25.4 mm. We write “=” only when a value is exact and “≈” when it is rounded. Comparison objects come only from official rules or published specifications.

How we check numbers

Frequently asked questions

What is DimensionVista?

DimensionVista is a free site of length converters and size guides. Each page gives the exact conversion first, then shows the size drawn to scale next to real objects.

How many mm is 1 inch?

1 inch is exactly 25.4 mm, by international definition (NIST SP 811).

How do I convert mm to inches?

Divide the millimeters by 25.4. For example, 8 mm ÷ 25.4 ≈ 0.315 inches, or about 5/16 inch.

How do I convert cm to inches?

Divide the centimeters by 2.54. For example, 20 cm ÷ 2.54 ≈ 7.87 inches.

Are the numbers checked?

Yes. Conversions come from fixed definitions and are generated by code, and objects used for comparison come from published rules or specifications. See How we check.

Can I print the charts?

Yes. The mm to inches page has a printable PDF chart, and printable versions will be added to other converter pages.

DimensionVista

Free length converters and visual size guides, checked against exact definitions.