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Convert decimal inches to a fraction
On the default, 2.4375″ converts to 2 7/16″ exactly at 16ths. Enter your own decimal measurement below.
FREE TOOL · CONSTRUCTION
Inches to Fraction Chart
A tape measure thinks in fractions, not decimals. Convert any decimal-inch measurement to the nearest 16th, 32nd, or 64th instantly — or find it in the lookup charts, the way drill bits and tapes are actually marked.
16ths chart — every tape-measure mark
Most tape measures mark down to 16ths of an inch — these are the fractions you will actually see on the blade. Print-friendly for the shop wall.
| Decimal inches | Fraction | Decimal inches | Fraction |
|---|---|---|---|
| 0.0625 | 1/16″ | 0.5625 | 9/16″ |
| 0.125 | 1/8″ | 0.625 | 5/8″ |
| 0.1875 | 3/16″ | 0.6875 | 11/16″ |
| 0.25 | 1/4″ | 0.75 | 3/4″ |
| 0.3125 | 5/16″ | 0.8125 | 13/16″ |
| 0.375 | 3/8″ | 0.875 | 7/8″ |
| 0.4375 | 7/16″ | 0.9375 | 15/16″ |
| 0.5 | 1/2″ | 1.0 | 1″ |
32nds chart — the in-between marks
Rulers, calipers, and many drill bits step in 32nds. These are the fractions that fall between the 16th marks above.
| Decimal inches | Fraction | Decimal inches | Fraction |
|---|---|---|---|
| 0.03125 | 1/32″ | 0.53125 | 17/32″ |
| 0.09375 | 3/32″ | 0.59375 | 19/32″ |
| 0.15625 | 5/32″ | 0.65625 | 21/32″ |
| 0.21875 | 7/32″ | 0.71875 | 23/32″ |
| 0.28125 | 9/32″ | 0.78125 | 25/32″ |
| 0.34375 | 11/32″ | 0.84375 | 27/32″ |
| 0.40625 | 13/32″ | 0.90625 | 29/32″ |
| 0.46875 | 15/32″ | 0.96875 | 31/32″ |
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Whole inches | drop everything after the decimal point | 2.4375″ keeps 2″; the rest becomes a fraction. |
| Fractional part | decimal remainder × chosen denominator, rounded | 0.4375 × 16 = 7 → 7/16″. |
| Simplified fraction | divide top & bottom by their GCD | 8/16 reduces to 1/2″ — the converter always gives you lowest terms. |
| Rounding error | |chosen fraction − exact decimal| | 2.4375 at 16ths rounds to exactly 0.0000″ of error. |
Worked example: 2.4375″ to the nearest 16th
Split off the whole inches: 2″ plus a remainder of 0.4375″. Multiply the remainder by 16: 0.4375 × 16 = 7 exactly, so the fraction is 7/16″. Reassemble: 2 7/16″. The rounding error is 0.0000″ — an exact conversion. For 2.44″ instead: 0.44 × 16 = 7.04 → rounds to 7 → 2 7/16″ = 2.4375″, a rounding error of only 0.0025″.
Who uses this
- Carpenters & framers: turning digital tape readouts (3.5625″) into blade marks (3 9/16″) at a glance.
- Machinists & metalworkers: caliper decimals to 32nds and 64ths — the language of tooling and drill-bit indexes.
- DIYers: figuring out which fractional drill bit matches a decimal-sized hole or fastener.
- 3D printing & crafters: converting CAD decimals into fractional measurements for pattern cutting.
Accuracy & limitations
The lookup charts are exact — every decimal shown is the true value of its fraction, verified. The converter rounds to the nearest mark of your chosen denominator, and the rounding error is always shown so you know exactly how much you gave up; at 16ths the worst case is half a 16th, or 0.03125″. Pick the denominator that matches the tool you will actually measure with — finer is not better if your tape only reads 16ths.
Going the other direction? The fraction to decimal chart converts fractions to decimals, and the decimal to fraction converter handles non-inch fractions of any kind.
Cite this calculatorBright Side Kit. “Inches to Fraction Chart.” brightoolbox.com, 2026.
Bright Side Kit. "Inches to Fraction Chart." https://brightoolbox.com/inches-to-fraction/ Accessed October 22, 2026.Frequently asked questions
Why does construction use fractions instead of decimals?
Halving is the whole job. Inches divide cleanly in half — half of 1/2 is 1/4, half of that is 1/8 — so fractions track naturally down the tape blade. Decimals shine when you need thousandths on a machine; fractions shine when a human is reading marks by eye.
Should I round to 16ths, 32nds, or 64ths?
Match the tool you are measuring with. A standard tape measure reads 16ths; many rulers and calipers read 32nds; drill bits are sold in 64ths (a 29-piece index). Finer than your tool is false precision — pick the coarsest denominator your tool can actually hit.
How do I convert a fraction back to decimal inches?
Divide the top by the bottom. 7/16 ″ = 7 ÷ 16 = 0.4375″. The fraction to decimal chart has every common fraction converted for you.
What about millimeters?
Metric avoids this entirely — millimeters are already decimal, so 1.5 mm needs no conversion. This page is for inch measurements, where fractional hardware (drill bits, wrenches, tapes) rules the shop.
Is 0.5 inches the same as 1/2 inch on a tape measure?
Exactly the same. 0.5 ÷ (1/16) = 8, so 0.5″ = 8/16″ = 1/2″ in lowest terms. The converter always simplifies, so you get the mark that actually appears on the blade.
Why does the converter show a rounding error?
So you know what the rounding cost you. A caliper reading of 2.44″ has no exact 16th equivalent — the nearest is 2 7/16″ (2.4375″), off by 0.0025″. For framing that is nothing; for machine work, switch to 64ths or stay decimal.