5/16 Inch to MM
Fractional inch to millimeters
5/16 inch (5/16″)
7.9375 mm
= 0.7937 cm · 1 inch = 25.4 mm exactly
💡 Commonly used for bolts and anchors.
Nearby fractional inches
| Fraction | mm | cm |
|---|---|---|
| 3/16″ | 4.7625 mm | 0.4762 cm |
| 1/4″ | 6.35 mm | 0.635 cm |
| 5/16″ | 7.9375 mm | 0.7937 cm |
| 3/8″ | 9.525 mm | 0.9525 cm |
| 7/16″ | 11.1125 mm | 1.1112 cm |
Also written as
5/16 to mm · 5/16 in mm · 5/16" in mm · 5/16 inch in mm · 5/16 inches to millimeters · 5/16 en mm · 0.3125 inch to mm
All of these mean the same measurement. The double-prime mark (″) and the plain quote (") both stand for inches, and en mm is simply the French and Spanish wording of the same question.
Closest metric drill size
8 mm
5/16″ = 7.9375 mm · difference 0.0625 mm
Metric drills step in 0.5 mm, so a fractional inch size rarely lands exactly on one. A 0.0625 mm gap is usually invisible in a clearance hole but changes the fit on a press fit or a tapped hole.
FAQ
How many mm is 5/16 inch?
5/16 inch equals 7.9375 mm. Since one inch is defined as exactly 25.4 mm, the result is 25.4 × 5 ÷ 16.
Why is the value exact?
The international yard and pound agreement of 1959 fixed the inch at exactly 25.4 mm, so fractional inch conversions terminate rather than repeat.