5/16 inches to mm = 7.9375 mm

Quick Answer: 5/16 inches = 7.9375 mm

inches → mm mm → inches
/ ″
Conversion Result
5/16″ = 7.9375 mm Decimal: 0.312500″

Exact conversion: 5/16″ × 25.4 = 7.9375 mm

Frequently Asked Questions

To convert inches to millimeters, multiply the inch value by 25.4.

Formula: mm = inches × 25.4

Example: 5/16″ × 25.4 = 7.9375 mm

1/4 inch = 6.35 mm exactly.

Calculation: 0.25 × 25.4 = 6.35 mm. Common for small fasteners, screws, and precision work.

3/8 inch = 9.525 mm exactly.

Calculation: 0.375 × 25.4 = 9.525 mm. One of the most common bolt and nut sizes in the US.

5/16 inch = 7.9375 mm exactly.

Calculation: 0.3125 × 25.4 = 7.9375 mm. Common for bolts, screws, and small hardware.

Yes, 3/8" is bigger than 5/16".

3/8" = 9.525 mm, while 5/16" = 7.9375 mm. The difference is 1.5875 mm (1/16"). To compare fractions, convert to the same denominator: 3/8 = 6/16, which is greater than 5/16.

1 inch = 25.4 millimeters exactly.

This is not an approximation—it's the exact definition established by the International Yard and Pound Agreement of 1959. The United States, United Kingdom, Canada, Australia, New Zealand, and South Africa all adopted this standard.

Similar Inches to MM Conversions

Values close to 5/16 inches for quick reference:

Inches Decimal Millimeters
0″ 0.000000 0 mm
1/16″ 0.062500 1.5875 mm
1/8″ 0.125000 3.175 mm
3/16″ 0.187500 4.7625 mm
1/4″ 0.250000 6.35 mm
5/16″ 0.312500 7.9375 mm
3/8″ 0.375000 9.525 mm
7/16″ 0.437500 11.1125 mm
1/2″ 0.500000 12.7 mm
9/16″ 0.562500 14.2875 mm
5/8″ 0.625000 15.875 mm

See Also

Frequently Asked Questions

How much is 5/16 inches in millimeters?

5/16 inches equals 7.9375 mm (exactly 0.312500 × 25.4 mm).

How do I convert 5/16 inches to mm?

Multiply inches by 25.4: 0.312500 × 25.4 = 7.9375 mm.

Is the conversion exact?

Yes. 1 inch = 25.4 mm exactly (1959 International Yard and Pound Agreement). All values on this page use this exact factor.

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5/16 inches to mm — 7.9375 mm

More inches to mm conversions

How to Convert Inches to Millimeters

One inch equals exactly 25.4 millimeters (by international agreement since 1959). To convert any inch value to millimeters, simply multiply by 25.4.

Conversion Formula

millimeters = inches × 25.4

Example: Convert 5/16 inches to mm

  1. Convert fraction to decimal: 5/16 = 0.312500 inches
  2. Multiply by 25.4: 0.312500 × 25.4 = 7.9375 mm

Result: 5/16″ = 7.9375 mm

Complete Fractional Inches to Millimeters Reference Table

All standard fractional inch values (64ths) with their exact millimeter equivalents. Click the link icon to share a specific conversion.

Fractional Inches to Millimeters
0″ to 31/64″

Inches Decimal Millimeters
0″0.0000000.0000 mm
1/64″0.0156250.3969 mm
1/32″0.0312500.7938 mm
3/64″0.0468751.1906 mm
1/16″0.0625001.5875 mm
5/64″0.0781251.9844 mm
3/32″0.0937502.3813 mm
7/64″0.1093752.7781 mm
1/8″0.1250003.1750 mm
9/64″0.1406253.5719 mm
5/32″0.1562503.9688 mm
11/64″0.1718754.3656 mm
3/16″0.1875004.7625 mm
13/64″0.2031255.1594 mm
7/32″0.2187505.5563 mm
15/64″0.2343755.9531 mm
1/4″0.2500006.3500 mm
17/64″0.2656256.7469 mm
9/32″0.2812507.1438 mm
19/64″0.2968757.5406 mm
5/16″0.3125007.9375 mm
21/64″0.3281258.3344 mm
11/32″0.3437508.7313 mm
23/64″0.3593759.1281 mm
3/8″0.3750009.5250 mm
25/64″0.3906259.9219 mm
13/32″0.40625010.3188 mm
27/64″0.42187510.7156 mm
7/16″0.43750011.1125 mm
29/64″0.45312511.5094 mm
15/32″0.46875011.9063 mm
31/64″0.48437512.3031 mm

Fractional Inches to Millimeters
1/2″ to 63/64″

Inches Decimal Millimeters
1/2″0.50000012.7000 mm
33/64″0.51562513.0969 mm
17/32″0.53125013.4938 mm
35/64″0.54687513.8906 mm
9/16″0.56250014.2875 mm
37/64″0.57812514.6844 mm
19/32″0.59375015.0813 mm
39/64″0.60937515.4781 mm
5/8″0.62500015.8750 mm
41/64″0.64062516.2719 mm
21/32″0.65625016.6688 mm
43/64″0.67187517.0656 mm
11/16″0.68750017.4625 mm
45/64″0.70312517.8594 mm
23/32″0.71875018.2563 mm
47/64″0.73437518.6531 mm
3/4″0.75000019.0500 mm
49/64″0.76562519.4469 mm
25/32″0.78125019.8438 mm
51/64″0.79687520.2406 mm
13/16″0.81250020.6375 mm
53/64″0.82812521.0344 mm
27/32″0.84375021.4313 mm
55/64″0.85937521.8281 mm
7/8″0.87500022.2250 mm
57/64″0.89062522.6219 mm
29/32″0.90625023.0188 mm
59/64″0.92187523.4156 mm
15/16″0.93750023.8125 mm
61/64″0.95312524.2094 mm
31/32″0.96875024.6063 mm
63/64″0.98437525.0031 mm

All values are exact. 1 inch = 25.4 mm exactly (by international definition since 1959).

Common Fractional Inches to MM Quick Reference

The most commonly searched fractional inch conversions. Click the link icon to share a specific conversion.

Inches Millimeters Use Case
1/16″ 1.5875 mm Precision work
1/8″ 3.175 mm Sheet metal
9/16″ 14.2875 mm Medium hardware
11/16″ 17.4625 mm Specialty bolts
13/16″ 20.6375 mm Large nuts
15/16″ 23.8125 mm Heavy hardware
1″ 25.4 mm Standard reference
1 1/2″ 38.1 mm Pipe fittings

All values are exact. 1 inch = 25.4 mm (international standard since 1959).

Related Converters

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All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.

Conversion factors verified against NIST, BIPM, ISO 80000-3 1 inch = 2.54 cm by international agreement (1959). Last reviewed: March 2026
Adilson Fernandes By Adilson Fernandes
Tiago Fernandes Reviewed by Tiago Fernandes