How to Convert Fractions to Millimeters (and Back)
Convert fractional inches to millimeters and decimal inches for high-precision hardware and tool specifications.
High-precision hardware and industrial equipment often use metric measurements (mm), while standard building materials still use imperial fractions (1/4", 3/8", etc.). Bridging this gap is essential for fitting fasteners or selecting drill bits.
Metric vs. Imperial Breakdown
1 inch is exactly 25.4 millimeters. To convert a fraction like 1/2", we first resolve it to a decimal (0.5") and then multiply by 25.4. This tool handles the process in one step.
Precision Standards
While 25.4 is the exact multiplier, many pros keep a '25' in their head for rough estimation. If you're building furniture or doing machine work, use the exact calculation to ensure your hardware fits the first time.
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