Where Is 5/16 on a Tape Measure?
Direct Answer: To find 5/16 on a tape measure, locate the 1/4" line (the longest tick between 0 and 1/2") and look one 1/16" tick mark to the right. In decimal form, 5/16 equals 0.3125 inches (or 7.938 millimeters).
5/16" Position on a 16ths Tape Measure Blade
5/16" is highlighted below — click anywhere on the yellow blade or select a fraction button to compare marks:
1/16" past the 1/4" mark (or 1/16" before 3/8")
How to Find 5/16" in 2 Seconds (Using the 1/4" Landmark)
Instead of counting five tiny ticks from zero, jump straight to the 1/4" mark (4/16") and move one 1/16" tick to the right:
Nearby Fractions Comparison Table
How 5/16" compares to the surrounding marks on a 16ths tape measure:
| Fraction | 16ths Equivalent | Decimal (Inches) | Millimeters (mm) | Position on Blade |
|---|---|---|---|---|
| 3/16" | 3/16" | 0.1875" | 4.763 mm | 2 ticks before 5/16" |
| 1/4" | 4/16" | 0.2500" | 6.350 mm | 1 tick immediately before 5/16" |
| 5/16" ★ | 5/16" | 0.3125" | 7.938 mm | Target measurement |
| 3/8" | 6/16" | 0.3750" | 9.525 mm | 1 tick immediately after 5/16" |
| 7/16" | 7/16" | 0.4375" | 11.113 mm | 2 ticks after 5/16" |
Common Mistakes Finding 5/16"
Confusing 5/16" with 5/8"
Because both start with 5, they are easy to mix up. Remember that 5/16" (0.3125") is well under half an inch, while 5/8" (0.625") is over half an inch.
Counting 1/8" Marks Instead of 1/16" Marks
Counting five 1/8" lines lands you at 5/8". Always count five of the shortest 1/16" lines (or start at 1/4" and add one 1/16" tick).
Drilling a 5/16" Pilot Hole for a 5/16" Lag Screw
Never drill a 5/16" hole into the receiving wood for a 5/16" lag screw—the threads will have nothing to bite into. Use a smaller pilot bit (typically 3/16" to 1/4" depending on wood hardness).
Using an 8 mm Socket on a High-Torque 5/16" Bolt
5/16" is 7.938 mm. An 8 mm socket is slightly looser by 0.062 mm and can round off tight or rusted 5/16" hex heads under high torque.
Frequently Asked Questions
Where is 5/16 on a tape measure?
5/16 inch is the fifth 1/16 mark after a whole inch. It sits one small line after the 1/4 inch mark and one small line before the 3/8 inch mark.
What is 5/16 in decimal and millimeters?
5/16 inch equals 0.3125 inches, which is 7.94 mm.
What does 5/16 look like on a tape measure?
It is one of the shortest lines on the tape (a 1/16 mark), sitting just past the slightly longer 1/4 inch line.
What is half of 5/16 on a tape measure?
Half of 5/16 is 5/32 inch (0.15625 in). A standard tape does not show 32nds (see our tape measure reading guide or our 5/8 guide), so it falls halfway between the 1/8 mark and the 3/16 mark.
How do I find measurements like 1 5/16, 2 5/16 or 34 5/16?
Find the whole inch number first (1, 2 or 34), then count 5 of the shortest lines past it. The fraction part is always the same 5/16 distance.
Is 5/16 bigger than 1/4?
Yes. 5/16 is 0.3125 inch and 1/4 is 0.25 inch. It is smaller than 3/8, which is 0.375 inch.