Drill Bit Size Calculator
Find Closest Drill Bit
Find the nearest standard drill bit to a decimal size
Formula
Fractional sizes = N/64 inch | Metric = Inches x 25.4 mm | Closest = min(|bit - target|)
Frequently Asked Questions
How do I choose the right drill bit size?
Match the drill bit to your purpose. For pilot holes, use a bit matching the screw root diameter. For clearance holes, match the shank diameter. For dowels, match the dowel exactly.
What is the difference between fractional and number drill bits?
Fractional bits come in 1/64 inch increments. Number bits (1-80) and letter bits (A-Z) fill in the gaps between fractional sizes for more precise sizing.
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