Fraction to Decimal Chart: Halves to Sixteenths 2026

What is 3/8 as a decimal? 0.375 — and why the chart stops at sixteenths

A fraction is a division waiting to happen: 3/8 means 3 divided by 8, which is 0.375, or 37.50%. The chart below lists the fractions you meet most — halves, thirds, quarters, fifths, eighths and sixteenths — with their decimals to four places and their percents to two. Sixteenths are the last row because they are the standard ruler and measurement grid: a tape measure is marked in sixteenths, so when a fraction does not land on one, the nearest sixteenth is the one you can actually measure. On the defaults — numerator 3, denominator 8 — the decimal is 0.3750, the percent is 37.50%, the simplest form is 3/8, and the nearest sixteenth is 3/8.

At the defaults — numerator 3, denominator 8 — the decimal is 0.3750, the percent is 37.50%, the simplest form is 3/8, and the nearest sixteenth is 3/8. Check the identities: decimal = numerator / denominator; percent = decimal × 100; simplest form = numerator and denominator divided by their greatest common divisor; nearest sixteenth = round(decimal × 16) / 16, reduced. A whole number shows as the number alone (5/5 is 1), and zero shows as 0. The decimals are rounded to four places and the percents to two — so 1/3 is 0.3333 and 33.33%, and 2/3 is 0.6667 and 66.67%: the two do not add to exactly 1.0000 or 100.00%, because each is rounded on its own.

The worked example, line by line

Setup: numerator 3, denominator 8.

Line 1 — the decimal. 3 ÷ 8 = 0.3750.

Line 2 — the percent. 0.3750 × 100 = 37.50%.

Line 3 — the simplest form. 3 and 8 share no common divisor but 1, so 3/8 is already simplest: 3/8.

Line 4 — the nearest sixteenth. 0.375 × 16 = 6, so the nearest sixteenth is 6/16 = 3/8 itself.

Reverse: the decimal for 5/8 is 0.6250. The percent for 7/16 is 43.75%. The fraction for the decimal 0.4375 is 7/16 exact (0.4375 × 16 = 7). The numerator for the decimal 0.125 with denominator 8 is 1 (1/8). The nearest sixteenth to 0.33 is 5/16 (0.3125, off by 0.0175) vs 3/8 (0.375, off by 0.045) — 5/16 is nearer.

Every branch, checked

1/2: decimal 0.5000, percent 50.00%, simplest 1/2, nearest sixteenth 1/2. A half is 8/16 — it lands exactly on the grid.

2/3: decimal 0.6667, percent 66.67%, simplest 2/3, nearest sixteenth 11/16. Two-thirds does not land on a sixteenth: 0.6667 × 16 = 10.6667, which rounds to 11, so 11/16 (0.6875) is the nearest.

5/16: decimal 0.3125, percent 31.25%, simplest 5/16, nearest sixteenth 5/16. It is a sixteenth already, so it is its own nearest.

7/8: decimal 0.8750, percent 87.50%, simplest 7/8, nearest sixteenth 7/8. Seven-eighths is 14/16 — it lands exactly on the grid.

1/3: decimal 0.3333, percent 33.33%, simplest 1/3, nearest sixteenth 5/16. A third does not land on a sixteenth: 0.3333 × 16 = 5.3333, which rounds to 5, so 5/16 (0.3125) is the nearest.

6/8: decimal 0.7500, percent 75.00%, simplest 3/4, nearest sixteenth 3/4. Six-eighths simplifies to three-quarters — the chart shows the simplest form, not the entered one.

10/4: decimal 2.5000, percent 250.00%, simplest 5/2, nearest sixteenth 5/2. An improper fraction works the same way: 10/4 is two and a half, and 5/2 is its simplest form.

0/5: decimal 0.0000, percent 0.00%, simplest 0, nearest sixteenth 0. Zero over anything is zero.

1/7: decimal 0.1429, percent 14.29%, simplest 1/7, nearest sixteenth 1/8. A seventh does not land on a sixteenth: 0.1429 × 16 = 2.2857, which rounds to 2, so 2/16 = 1/8 is the nearest.

22/7: decimal 3.1429, percent 314.29%, simplest 22/7, nearest sixteenth 25/8. The pi approximation as a fraction: 3.1429 × 16 = 50.2857, which rounds to 50, so 50/16 = 25/8 is the nearest sixteenth.

Reverse — the other way round: the decimal for 5/8 is 0.6250; the percent for 7/16 is 43.75%; the fraction for the decimal 0.4375 is 7/16 exact; the numerator for the decimal 0.125 with denominator 8 is 1; the nearest sixteenth to 0.33 is 5/16.

What the chart assumes

The chart assumes exact arithmetic: fractions are exact by definition, decimals are rounded to four places, and percents to two. It assumes the nearest sixteenth is the one a ruler can show — round the decimal times 16 to the nearest whole number, then reduce. It leaves out thirty-seconds and sixty-fourths, which machinists use but tape measures do not, and it leaves out repeating decimals beyond four places: 1/3 is 0.3333 here, not 0.333333…. With 0/5 the answer is 0.0000 and 0.00%, simplest 0, nearest sixteenth 0. With 5/5 the answer is 1.0000 and 100.00%, simplest 1, nearest sixteenth 1. With 1/1 the answer is the same: 1.0000, 100.00%, 1, 1. With a denominator of 0, or a numerator outside 0–1,000, the calculator shows an error, not a decimal, because the model is a fraction model and it needs a fraction in range.

Output · formula · meaning

Who uses this

• The cook halving a recipe: they learn 3/8 of a cup is 0.375 — so they know what the measuring cup should read, and they check the 1/3 row (0.3333) before guessing at a third of a cup.
• The DIYer reading a tape measure: they learn 2/3 of an inch is nearest to 11/16 — so they know which mark to cut on, and they check the 1/7 row (1/8) before cutting a seventh to the nearest mark.
• The student checking homework: they learn 6/8 simplifies to 3/4 and equals 0.7500 — so they know the simplest form is what the teacher wants, and they check the 10/4 row (5/2) before leaving an improper fraction unsimplified.
• The sewer or crafter converting a pattern: they learn 7/16 is 0.4375 exactly — so they know a decimal that stops at four places has an exact sixteenth, and they check the 0.33 reverse (5/16) before rounding a measurement to the nearest mark.

Accuracy & limitations

The math is exact for the numbers you enter: decimal = numerator / denominator; percent = decimal × 100; simplest form = numerator and denominator divided by their greatest common divisor; nearest sixteenth = round(decimal × 16) / 16, reduced. The decimals are rounded to four places and the percents to two — so 1/3 is 0.3333 and 33.33%, and 2/3 is 0.6667 and 66.67%: the two do not add to exactly 1.0000 or 100.00%, because each is rounded on its own. What the chart cannot do is show a fraction more precisely than four decimal places: check the decimal, because 1/3 is 0.3333 here, not 0.333333…. It assumes sixteenths are the measurement grid and leaves out thirty-seconds and sixty-fourths. It is a fraction reference, not a maths tutor: for adding fractions, see the add fractions calculator; for percents, see the percentage calculator; for ratios, see the ratio to fraction calculator.