Online RulerHow to Read Eighths on a Ruler
On a ruler divided into eighths, each space is 1/8 inch. Find the whole inch just before the endpoint, then count the eighth-inch spaces after it. An endpoint five spaces past 6 inches reads 6 5/8 inches. On a scale divided into sixteenths, count pairs of spaces to read eighths.
- Eight equal spaces make one inch. The whole-inch lines at either end mark the boundaries.
- The quarter, half, and three-quarter lines sit at 2/8, 4/8, and 6/8 of an inch.
- Odd eighths keep 8 as the denominator when reduced. Even eighths reduce to quarters, halves, or a whole inch.
- Look at one full inch of the scale. Count the spaces to see whether the ruler divides it into eighths or sixteenths.
- Set one end of the object at zero. Hold the ruler still and look straight down at the other end.
- Find the numbered inch at or before the endpoint. On an eighth-inch scale, count each space from there. On a sixteenth-inch scale, count every pair of spaces.
- Write the number of whole inches and the fraction. If you need the nearest eighth and the endpoint sits between eighth marks, choose the closer one.
Find the odd eighths
Use the quarter and half marks to locate the odd eighths. The 1/8 mark is halfway from zero to 1/4. The 3/8 mark is halfway from 1/4 to 1/2. Past the middle, 5/8 lies halfway from 1/2 to 3/4, and 7/8 lies halfway from 3/4 to the next inch.
Check the mark on a busy scale
When the ruler has sixteenths, locate the halfway line first. It is 4/8 into the inch. For 5/8, move two of the smallest spaces toward the next inch. The first small line after the halfway line is 9/16. The second line is 10/16, which is the same as 5/8.
Lay out a row of marks
For marks spaced 3/8 inch apart, leave zero at the same starting point. Place the first mark at 3/8, the second at 6/8, and the third at 1 1/8. Check each position from zero. This keeps a pencil mark that is slightly off from shifting the rest of the row.
Is 4/8 the same as half an inch?
Yes. Four eighths fill half of the eight spaces in an inch. Both fractions point to the same line.
How many small lines are inside an inch on an eighth-inch ruler?
There are seven interior lines. Together with the two whole-inch boundary lines, they form eight spaces.
What if the two closest eighth marks are equally far away?
If your task gives a rounding rule, follow it. If you can record sixteenths, write the midpoint reading. For example, the midpoint between 1/4 and 3/8 is 5/16.