Fraction to Decimal Chart | Inch Conversion Reference

A fraction to decimal chart provides quick reference conversions between fractional inch measurements and their decimal equivalents, commonly used by contractors, machinists, and DIY builders for precise measurements.

Fraction to Decimal Conversion Chart

Use this interactive fraction to decimal conversion chart to convert between fractional inch measurements and decimal equivalents. It is one of the reference charts available on this site. This is geared toward contractors, carpenters, machinists, and DIY builders who bounce between tape measure fractions and decimal readouts.

Interactive Conversion Chart

16 rows

Quick Converter

/
= Enter a fraction
Fraction (in) Decimal (in) Millimeters
1/16" 0.0625 1.59
1/8" 0.1250 3.17
3/16" 0.1875 4.76
1/4" 0.2500 6.35
5/16" 0.3125 7.94
3/8" 0.3750 9.52
7/16" 0.4375 11.11
1/2" 0.5000 12.70
9/16" 0.5625 14.29
5/8" 0.6250 15.88
11/16" 0.6875 17.46
3/4" 0.7500 19.05
13/16" 0.8125 20.64
7/8" 0.8750 22.22
15/16" 0.9375 23.81
1" 1.0000 25.40

How to Use This Conversion Chart

  • Select the Fraction → Decimal tab if you have a fraction from a tape measure and need a decimal for a calculator, CNC, or layout software.
  • Select the Decimal → Fraction tab if you have a decimal from a caliper, laser, or plan and need a tape-friendly fraction. For a dedicated reference, see the decimal to fraction inches chart.
  • Use Common (16ths) for framing/general carpentry, Detailed (32nds) for finish work, and Precision (64ths) when you need machinist-level accuracy.
  • Use the Quick Converter for odd fractions/decimals that are not obvious or aren’t in the portion of the table you’re viewing.

Common Fraction to Decimal Conversions

These are the conversions tradespeople hit constantly on site or in the shop.

FractionDecimal (in)MillimetersTypical use
1/16”0.06251.59Small shims, reveals, fine adjustments
1/8”0.12503.18Small gaps, siding reveals, drill bits
3/16”0.18754.76Underlayment, thin stock, spacers
1/4”0.25006.35Plywood, spacer blocks, hardware layout
5/16”0.31257.94Bolt/lag clearances, plate offsets
3/8”0.37509.53Plywood, plate/ledger offsets
1/2”0.500012.70Drywall thickness, sheathing, pipe/bolt sizing
5/8”0.625015.88Drywall (fire-rated), deck boards, furring
3/4”0.750019.05Plywood, subfloor, hardwood thickness
7/8”0.875022.23Trim stock, stair parts
1”1.000025.40Base unit, nominal lumber dimensions

Precision Levels: 16ths, 32nds, 64ths

  • 16ths: Good enough for framing, deck joists, rafters, and most rough work (±0.0625”). See the dedicated 16ths of an inch chart for a focused, printable reference.
  • 32nds: Used for casing, baseboard, cabinetry, and trim where visible gaps matter (±0.03125”). See the dedicated 32nds of an inch chart for a focused reference.
  • 64ths: Used around metal, jigs, CNC, and precision setup where you’re matching shop drawings or machine tolerances (±0.015625”). See the dedicated 64ths of an inch chart for a focused reference.

Tape Measure Reality vs Decimal Tools

Most job-site tapes mark inches as fractions, while calculators, layout tools, lasers, and design software speak decimals. This chart keeps you from doing risky head-math every time you bounce between them, especially on repetitive cuts or expensive material.

Metric (mm) Column

The chart also shows millimeter equivalents so you can match metric hardware, Euro hinges, or metric shop drawings to your Imperial tape. One inch is exactly 25.4 mm, so every row in the chart multiplies the decimal inches by 25.4 to give you a quick mm reference. For a dedicated three-column reference with a bidirectional converter, see the fractions, decimals and millimeters chart.

Common Mistakes This Chart Helps Avoid

  • Mixing decimal feet and decimal inches when reading plans or survey stakes.
  • Rounding decimals too early and landing on the wrong fraction on your tape.
  • Guessing at metric equivalents and choosing the wrong drill bit, anchor, or fastener size.

Use the chart or the Quick Converter any time the number will cost you money if it’s wrong—long runs of material, CNC programming, stair layout, or structural hardware placement.

This chart pairs well with the roofing calculator for converting fractional pitch measurements and with the flooring calculator for converting plank dimensions to decimal inches.

  • Drywall Calculator — Estimate sheets and materials for drywall projects where 1/2” and 5/8” thickness fractions are standard measurements.
  • Roofing Calculator — Calculate shingle bundles and squares using roof pitch values that often involve fractional conversions.
  • Flooring Calculator — Convert fractional plank dimensions to decimal inches for accurate coverage-per-box calculations.
  • Lumber Dimensions Chart — Look up nominal vs actual lumber sizes where fractional dimensions like 1-1/2” and 3-1/2” are standard.

Frequently Asked Questions

Common questions about fraction to decimal conversions, reading tape measures, and precision measurements.

How do I convert a fraction to a decimal?
Divide the numerator (top number) by the denominator (bottom number). For example, 3/8 = 3 ÷ 8 = 0.375. For quick reference without calculation, use the conversion chart above which shows all common fractional inch measurements from 1/64 to 1 inch with their decimal equivalents.
What is 1/16 inch in decimal?
1/16 inch equals 0.0625 in decimal form. This is one of the most commonly used fractional measurements in construction and woodworking. To remember it, note that 1 ÷ 16 = 0.0625, or you can think of it as 6.25 hundredths of an inch.
How accurate does my measurement need to be?
For general carpentry and framing, 1/16 inch (0.0625) accuracy is typically sufficient. For finish carpentry and cabinetry, work to 1/32 inch (0.03125). For machining and precision metalwork, use 1/64 inch (0.015625) or finer. Always check project specifications for required tolerances.
Why do tape measures use fractions instead of decimals?
Traditional Imperial tape measures use fractions because they're easier to visualize and divide by hand - you can easily find 1/2, 1/4, 1/8, etc. by folding or halving. However, digital tools, calculators, and CNC machines use decimals, which is why contractors frequently need to convert between the two systems.
What's the difference between 16ths, 32nds, and 64ths?
These refer to measurement precision: 16ths divide each inch into 16 parts (1/16 = 0.0625), 32nds into 32 parts (1/32 = 0.03125), and 64ths into 64 parts (1/64 = 0.015625). Use 16ths for general work, 32nds for detailed work, and 64ths for precision machining or fine adjustments.
How do I read a fraction on a tape measure?
Tape measures show the largest marks for inches, medium marks for common fractions (1/2, 1/4), and progressively smaller marks for 1/8, 1/16, and sometimes 1/32. Count the number of small marks from the last inch mark and identify the fraction. For example, the 3rd mark after an inch on a 16ths tape is 3/16 inch.
Can I convert decimal feet to fractional inches?
Yes. First, separate the whole feet from the decimal portion. Then multiply the decimal portion by 12 to get inches, and convert that to a fraction. For example, 5.375 feet = 5 feet + (0.375 × 12) = 5 feet + 4.5 inches = 5 feet 4-1/2 inches.
What is 0.375 as a fraction?
0.375 equals 3/8 inch. This is a very common measurement in construction. To convert any decimal to a fraction, find the closest match in a conversion chart, or multiply by 64 (for 64ths precision): 0.375 × 64 = 24, so 24/64 = 3/8 when simplified.
Why does my calculator show 0.333 for 1/3 but charts show 0.3333?
1/3 is a repeating decimal (0.333...) that goes on forever. Charts typically show 4 decimal places (0.3333) for practical use, but it's technically inexact. For precision work, keep the fraction form (1/3) rather than converting to avoid rounding errors in calculations.
How do I convert millimeters to fractional inches?
Divide millimeters by 25.4 to get decimal inches, then use a conversion chart to find the closest fraction. For example, 10mm ÷ 25.4 = 0.3937 inches, which is approximately 25/64 inch (0.3906) or 3/8 inch (0.375) depending on required precision.

Fraction to Decimal Chart Summary

This page provides an interactive fraction to decimal conversion chart with printable tables showing conversions from 1/64 inch to 1 inch. Switch between common (16ths), detailed (32nds), and precision (64ths) views, or use the built-in calculator for custom conversions.

Printable Fraction Decimal Chart

Use the print button on the chart above, or press Ctrl+P to print this page as a reference sheet.

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