Length Conversion Chart
Use this printable length chart for common metric, imperial, nautical, and typography conversions. It is designed for quick reference, while the live converter handles arbitrary values and full unit tables.
| Unit | Metric reference | Imperial or print reference | Use note |
|---|---|---|---|
| Millimeters | 1 millimeter | 0.0393700787 inch | Useful for measurement and scale checks. |
| Centimeters | 1 centimeter | 0.3937007874 inch | Useful for measurement and scale checks. |
| Meters | 1 meter | 3.280839895 feet | Useful for measurement and scale checks. |
| Kilometers | 1 kilometer | 0.6213711922 mile | Useful for measurement and scale checks. |
| Inches | 1 inch | 25.4 millimeters | Useful for measurement and scale checks. |
| Feet | 1 foot | 0.3048 meter | Useful for measurement and scale checks. |
| Yards | 1 yard | 0.9144 meter | Useful for measurement and scale checks. |
| Miles | 1 mile | 1.609344 kilometers | Useful for measurement and scale checks. |
| Nautical miles | 1 nautical mile | 1852 meters | Useful for measurement and scale checks. |
| Points | 1 point | 1/72 inch | Useful for typography and layout. |
| Picas | 1 pica | 1/6 inch | Useful for typography and layout. |
Exact inch
1 inch equals exactly 25.4 millimeters, anchoring feet, yards, points, and picas.
Metric prefixes
Millimeters, centimeters, meters, and kilometers scale by powers of ten.
Print units
Points and picas are included for layout and typography checks.
Choose the factor first, then round the result
A conversion factor can be exact even when the measured quantity is not. This chart distinguishes defined metric-customary relationships from convenient decimal displays so a lookup does not imply more accuracy than the original measurement supports.
Anchor relationships used by this chart
These factors connect the metric, international customary, nautical, and print units represented in the table.
- International inch
- 1 inch = exactly 25.4 millimeters.
- International foot
- 12 inches = exactly 0.3048 meter.
- International mile
- 5280 international feet = exactly 1609.344 meters.
- Nautical mile
- 1 nautical mile = exactly 1852 meters.
- PostScript point
- 1 point = 1/72 inch.
- Pica
- 1 pica = 12 points = 1/6 inch.
Exact definitions do not create measurement precision
Twelve inches converts to exactly 304.8 millimeters because the inch factor is defined exactly. If the original length was recorded only as 12 inches to the nearest inch, however, 304.8 millimeters should not be interpreted as a sub-millimeter measurement.
Carry sufficient digits through the multiplication, then round the final answer to a precision appropriate for the source value and task. Avoid rounding the factor before the calculation when an exact defined relationship is available.
Keep reference-chart and live-converter jobs separate
The chart is optimized for one-unit anchors and print lookup. It makes relationships such as an inch to millimeters or a point to an inch easy to scan and copy.
Open the live length converter for arbitrary source values, scientific notation, or comparison across the full supported unit set. That avoids mentally scaling a one-unit row when the input is large, small, or fractional.
Identify the foot before using legacy records
This page uses the international foot. It does not substitute the former U.S. survey foot that appears in some historic land-survey and geospatial records.
When a source dataset names a different realization of a unit, preserve that definition through the calculation. A modern international-foot chart should not silently relabel legacy coordinates or boundary measurements.
Worked check: convert one foot to millimeters
- 1Start with 1 foot = 12 inches.
- 2Apply the exact factor 25.4 millimeters per inch: 12 × 25.4 = 304.8.
- 3Report 304.8 millimeters as the defined equivalent, then apply task-appropriate rounding only if the source measurement itself was approximate.
Copying and printing guidance
- Decimal factors in the table are formatted for readable reference. Copy the exact definition when one is listed, especially for chains of calculations.
- Typography points here follow the 72-points-per-inch print convention. Other historical point systems are outside the chart's scope.
- The four-column table owns its horizontal scrolling on a phone. For paper, landscape orientation usually retains the note column more legibly than fit-to-page shrinking.
Sources and definitions
- NIST SP 811, Appendix B: conversion factors
Primary U.S. metrology reference for SI and customary conversion relationships.
Length chart questions
What is the most important exact length conversion?
The exact inch relationship is one of the most important length conversions for print and imperial work: 1 inch equals exactly 25.4 millimeters. Feet, yards, points, and picas all connect back through that relationship.
Why include points and picas in a length chart?
Points and picas are print and typography length units. They are useful when layout measurements, font sizes, and page design values need to be compared with inches or millimeters.
Is a nautical mile the same as a mile?
No. A nautical mile is exactly 1852 meters, while an international mile is exactly 1609.344 meters. Nautical miles are used in marine and aviation contexts rather than ordinary road-distance work.
Can I use this chart instead of the live converter?
Use the chart for common reference values and printed lookup work. Use the live length converter when the source value is not one unit, when scientific notation is needed, or when you need every supported unit in a full table.
Does the chart use the survey foot?
No. The chart uses the international foot based on the exact inch relationship. Older U.S. survey-foot references should be handled separately when working with legacy land-survey data.
Who maintains this page
Ownership and review
Written and maintained by the Toolarithm editorial team. No review date is shown without a maintained editorial record. No independent professional review is claimed.
Methodology
The editorial team checks definitions, examples, linked tools, and cited references. Dates shown here come from the page's maintained publication record.
Read the editorial methodologyDates and sources
Review dates change only after a substantive method or content check.
Sources: SI meter relationships from NIST SI length references, exact inch relationship through SI-based customary definitions, and nautical mile as 1852 meters.