Standard Fraction to Decimal and Metric Conversions
The Essential Guide for Precise Steel Measurements
A standard fraction to decimal and metric conversion chart is an indispensable tool for fabricators, machinists, and engineers. Whether you are measuring the width of a steel plate, the diameter of a pipe, or the thickness of a structural beam, precision is the foundation of a successful build.
The conversion table below provides a quick reference to jump between US customary fractions and decimals to their metric (millimeter) equivalents, ensuring your project meets exact specifications every time.
| Fraction (in) | Decimal (in) | Millimeters (mm) |
|---|---|---|
| 1/64 | 0.015625 | 0.396 |
| 1/32 | 0.03125 | 0.793 |
| 3/64 | 0.046875 | 1.19 |
| 1/16 | 0.0625 | 1.587 |
| 5/64 | 0.078125 | 1.984 |
| 3/32 | 0.09375 | 2.381 |
| 7/64 | 0.109375 | 2.778 |
| 1/8 | 0.125 | 3.175 |
| 9/64 | 0.140625 | 3.571 |
| 5/32 | 0.15625 | 3.968 |
| 11/64 | 0.171875 | 4.365 |
| 3/16 | 0.1875 | 4.762 |
| 13/64 | 0.203125 | 5.159 |
| 7/32 | 0.21875 | 5.556 |
| 15/64 | 0.234375 | 5.953 |
| 1/4 | 0.25 | 6.35 |
| 17/64 | 0.265625 | 6.746 |
| 9/32 | 0.28125 | 7.143 |
| 19/64 | 0.296875 | 7.54 |
| 5/16 | 0.3125 | 7.937 |
| 21/64 | 0.328125 | 8.334 |
| 11/32 | 0.34375 | 8.731 |
| 23/64 | 0.359375 | 9.128 |
| 3/8 | 0.375 | 9.525 |
| 25/64 | 0.390625 | 9.921 |
| 13/32 | 0.40625 | 10.318 |
| 27/64 | 0.421875 | 10.715 |
| 7/16 | 0.4375 | 11.112 |
| 29/64 | 0.453125 | 11.509 |
| 15/32 | 0.46875 | 11.906 |
| 31/64 | 0.484375 | 12.303 |
| 1/2 | 0.5 | 12.7 |
| 33/64 | 0.515625 | 13.096 |
| 17/32 | 0.53125 | 13.493 |
| 35/64 | 0.546875 | 13.89 |
| 9/16 | 0.5625 | 14.287 |
| 37/64 | 0.578125 | 14.684 |
| 19/32 | 0.59375 | 15.081 |
| 39/64 | 0.609375 | 15.478 |
| 5/8 | 0.625 | 15.875 |
| 41/64 | 0.640625 | 16.271 |
| 21/32 | 0.65625 | 16.668 |
| 43/64 | 0.671875 | 17.065 |
| 11/16 | 0.6875 | 17.462 |
| 45/64 | 0.703125 | 17.859 |
| 23/32 | 0.71875 | 18.256 |
| 47/64 | 0.734375 | 18.653 |
| 3/4 | 0.75 | 19.05 |
| 49/64 | 0.765625 | 19.446 |
| 25/32 | 0.78125 | 19.843 |
| 51/64 | 0.796875 | 20.24 |
| 13/16 | 0.8125 | 20.637 |
| 53/64 | 0.828125 | 21.034 |
| 27/32 | 0.84375 | 21.431 |
| 55/64 | 0.859375 | 21.828 |
| 7/8 | 0.875 | 22.225 |
| 57/64 | 0.890625 | 22.621 |
| 29/32 | 0.90625 | 23.018 |
| 59/64 | 0.921875 | 23.415 |
| 15/16 | 0.9375 | 23.812 |
| 61/64 | 0.953125 | 24.209 |
| 31/32 | 0.96875 | 24.606 |
| 63/64 | 0.984375 | 25.003 |
| 1 | 1 | 25.4 |
Why Consistent Unit Conversion Matters in Metal Fabrication
In the world of steel supply, small discrepancies can lead to big problems. Understanding how to navigate different units of measurement is critical for several reasons:
-
Precision Cutting: When using advanced services like Water Jet Cutting or plasma cutting, measurements are often programmed in decimals. Converting your fractional blueprint accurately ensures the final piece fits perfectly.
-
International Compatibility: Many industrial projects utilize a mix of domestic and imported components. Being able to quickly convert inches to millimeters allows for seamless integration of parts.
-
Material Selection: Steel widths and thicknesses are often listed in fractions by suppliers but required in decimals for engineering software. This chart bridges that gap instantly.
How to Convert Fractions to Decimals and Millimeters
While this chart provides a quick lookup, the math behind the conversions is straightforward for manual verification:
-
Fraction to Decimal: Divide the top number (numerator) by the bottom number (denominator).
-
Example: 5/8" → 5 ÷ 8 = 0.625"
-
-
Decimal to Millimeters: Multiply the decimal inch value by 25.4.
-
Example: 0.625" x 25.4 = 15.875 mm
-
Standard Measurement for Steel, Aluminum, and Alloys
Whether you are working with A36 Carbon Steel, Stainless Steel, or Aluminum, the physical dimensions remain constant. This reference data is essential for quality assurance and material selection across all industries, from residential home building to aerospace manufacturing.
Using standardized conversion data ensures that when you order a specific width from Warrenton Steel, you are receiving a product that aligns with industry-recognized ASTM and ISO measurement standards.
Based on Industry Standards
The values provided in our conversion charts are intended for educational and reference purposes, adhering to standard mathematical rounding for industrial applications. By following these recognized conversion factors, you ensure repeatable accuracy across your entire production workflow.
Contact us today for a quote.
Choosing the right measurements is only half the battle—choosing the right partner is the other. For all your structural steel, pipe, tube, and specialty metal needs, trust the experienced team at Warrenton Steel. We provide top-quality certified metals with the precision you demand.
Let’s talk Business.
Sign Up For Our Newsletter
Get invaluable insight sent directly to your inbox!