Inches to Fraction Converter
1.375 inches rounds to 1 3/8 inches on a tape measure. This inches to fraction converter turns decimal inches into the nearest common shop fraction, from halves through 64ths. Switch modes to enter a mixed fraction like 2 5/16 and turn it back into decimal inches for layouts, cut lists, drawings, and drill charts.
Quick answer
Pick the denominator that matches your tape, rule, or print, such as 1/16 or 1/32.
Match the rounding step to your tape, rule, print, or drill chart.
Result
1 3/8 in
Decimal inches
1.375 in
Rounded decimal
1.375 in
Precision
Nearest 1/16 in
What this tells you
- •Pick the denominator that matches your tape, rule, or print, such as 1/16 or 1/32.
- •The converter rounds the decimal part of the inch to the nearest mark at that precision.
- •Fraction results are simplified, so 26/64 shows as 13/32.
- •Mixed fractions like 1 3/8, simple fractions like 3/4, and whole inches all parse in reverse mode.
How to Use
- 1Choose decimal to fraction or fraction to decimal mode.
- 2Enter the inch value or mixed fraction.
- 3Select the denominator you want to round to, from 2 through 64.
- 4Read the nearest fraction and decimal inch values below.
How It Works
Formula
nearest fraction = whole inches + round(decimal part × denominator) / denominatorSplit the measurement into whole inches and the decimal remainder. Multiply the remainder by the selected denominator, round to the nearest whole numerator, then simplify the fraction. To go back to decimal inches, add the whole inches to the numerator divided by the denominator. For example, 2.3125 inches at 1/16 precision gives 0.3125 × 16 = 5, so the result is 2 5/16 inches.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Convert 1.375 inches to a fraction
0.375 inches is 6/16, which simplifies to 3/8, so the nearest 1/16 mark is 1 3/8 in.
Convert 0.40625 inches to a fraction
0.40625 inches is 26/64, which simplifies to 13/32 while keeping 1/64 precision.
Convert 2 5/16 inches to decimal
Add the whole inches to 5 divided by 16. That gives 2 + 0.3125 = 2.3125 inches.
Common Decimal Inch Equivalents
Handy shop and construction fractions you see on rules, tapes, and drill charts.
| Decimal inches | Nearest fraction | Nearest 64th mark |
|---|---|---|
| 0.125 | 1/8 in | 8/64 in |
| 0.1875 | 3/16 in | 12/64 in |
| 0.375 | 3/8 in | 24/64 in |
| 0.625 | 5/8 in | 40/64 in |
| 0.8125 | 13/16 in | 52/64 in |
| 1.375 | 1 3/8 in | 1 24/64 in |
| 2.3125 | 2 5/16 in | 2 20/64 in |
Fractions are simplified in the result card, even when the rounding step is 1/32 or 1/64.
Common mistakes
- Picking the wrong denominator for the job. Cabinet layouts often use 1/32 while framing tape calls usually stop at 1/16.
- Reading the decimal digits as a fraction. 1.375 inches is not 1 and 375 over 1000. It is 1 and 3/8 inches.
- Rounding twice. Keep the original decimal until the last step, especially when you are stacking several cuts or offsets.