MM to Inches Conversion Chart
Generate and print custom millimeters to inches conversion charts. Choose your preferred range, precision, and format for quick reference.
Chart Settings
Chart Preview: 0mm to 100mm, step 2mm • 51 rows
Chart Preview
How to use this mm to inches chart
Use this mm to inches chart as a printable reference for common metric sizes. Choose the range, precision, and format in the chart generator, then print or save the result for a workshop, classroom, product desk, or project binder. The chart uses the exact standard 1 inch = 25.4 mm, so decimal values come from millimeters ÷ 25.4.
Common millimeter sizes in inches
Small sizes: 1 mm to 10 mm
Small metric values are common in parts, hardware, crafts, and product details. Use decimal inches for precision and a fraction only when a ruler-style approximation is useful.
Workshop and product sizes: 25.4 mm, 50 mm, 100 mm
25.4 mm is exactly 1 inch. Larger values such as 50 mm and 100 mm are useful for product dimensions, packaging, woodworking, and general project references.
Printable chart notes
For printouts, choose a range that matches your use case. A compact 0–100 mm chart works well for small parts and classroom practice, while larger project references may need 0–300 mm or a custom range.
Related inches-to-mm fractions
Starting with a ruler fraction instead of a millimeter value? Use the inches to mm chart or open a dedicated fraction page for exact values such as 1/4 inch = 6.35 mm, 3/8 inch = 9.525 mm, 1/2 inch = 12.7 mm, 5/16 inch = 7.9375 mm, and 7/8 inch = 22.225 mm.
Choosing the right row from the mm to inches chart
Match precision to the job
For product copy, classroom work, quick shop references, and rough comparisons, two decimal places in inches are usually easy to read. For machining notes, CAD dimensions, replacement parts, or inspection reports, keep more decimal places until you know the tolerance. The chart can help you see both the friendly rounded value and the more exact decimal before you decide which one belongs in the final note.
Avoid using a nearby fraction as a substitute without context. A value may look close on a ruler but still be too different for a tight slot, bearing, pin, fastener, enclosure, or printed part. If the part must fit another part, compare the converted inch value with the allowed tolerance rather than choosing the nearest familiar fraction.
Keep labels consistent
When you copy values from the chart into a drawing, listing, worksheet, or spreadsheet, keep the same order and unit labels throughout the document. Write length, width, and height in the same sequence as the source measurement, and separate product dimensions from package dimensions so the converted numbers do not get mixed together.
For printed reference sheets, add a small note explaining that 1 inch equals exactly 25.4 mm and that displayed decimals may be rounded. That note makes the chart easier to use later because readers know whether a number is exact, rounded for display, or only a quick comparison.
Need fraction to mm?
Open the fractional inches to mm chart or jump directly to common ruler fractions.
Related printable charts
Need more shop, classroom, or reference tables? These printable chart resources pair well with this mm to inches chart.
Customizable Ranges
Generate charts for any range from 0.1mm to 5000mm. Perfect for specific project needs.
Adjustable Precision
Choose decimal precision (2-6 places) and fractional formats (1/8", 1/16", 1/32") for your needs.
Print Ready
Optimized for printing. Clean layout perfect for workshop walls, toolboxes, or quick reference.
Common Use Cases
🔧 Workshop & Manufacturing
Keep a printed chart on your workshop wall for quick reference when working with metric and imperial measurements.
📐 Engineering & Design
Generate precise conversion tables for technical drawings and specifications with high decimal accuracy.
🎓 Education & Training
Print charts for classroom use to help students learn metric and imperial unit conversions.
🛠️ Home Projects
Keep handy reference tables for DIY projects, furniture assembly, and home improvements.
Frequently Asked Questions
What is the formula behind the mm to inches chart?
The chart uses inches = millimeters ÷ 25.4.
Is 25.4 mm exactly 1 inch?
Yes. 1 inch is defined as exactly 25.4 millimeters.
Can I print this chart?
Yes. Generate the chart, then use the print option or your browser’s print dialog to print or save it as a PDF.
Which values should I use for product dimensions or worksheets?
For products, use decimal inches and keep rounding consistent. For worksheets, choose common values such as 10 mm, 25.4 mm, 50 mm, and 100 mm so students can practice the formula.
Need Quick Conversions?
Use our interactive converter for instant conversions without creating a full chart.
Go to Interactive ConverterEditorial conversion notes
How to use this conversion accurately
Formula
1 inch = 25.4 millimeters exactly.
Rounding, tolerance, and substitution
Millimeters are divided by 25.4. Decimal columns may be rounded to the chosen precision; fraction columns are approximations at the selected denominator unless the value is exact.
Practical use cases
- Generate a custom millimeter range for workshop, office, or classroom lookup.
- Choose decimal precision and use fraction equivalents as quick reading aids.
Comparisons and examples
- 12.7 mm = 0.5 inch exactly; 25.4 mm = 1 inch exactly; 100 mm ≈ 3.9370 inches.
- For fit decisions, follow the exact decimal result and stated tolerance rather than the nearest chart fraction.
Editorial value
Explain chart settings, exact-versus-rounded columns, and print checks, with contextual paths to use-case tools.