Inches to cm Converter (in ↔ cm)
The Inches to cm Converter translates U.S. measurements into metric length using the exact factor 1 inch = 2.54 centimeters. It’s useful when reading international product specs, planning woodworking or sewing projects with mixed units, checking screen sizes, or comparing dimensions across regions without mental math.
Enter any inch value (whole, decimal, or common fractions) and get a precise centimeter result, with optional rounding for practical cut lists. The goal is quick, error-free unit conversion so you can order parts confidently, match plans to tools, and keep measurements consistent from sketch to build. Type a number and move on with clarity.
Convert inches (in) to centimeters (cm) — with fraction helper, size shortcuts, and instant results.
Enter either inches or centimeters
Inches to cm Results
How inches and centimeters convert
Formulas, steps, assumptions
Formulas: cm = in × 2.54 (exact); in = cm ÷ 2.54.
Steps: Enter a value ➝ choose rounding ➝ optionally show a fraction-inch ➝ copy a link with your inputs.
Assumptions: International inch; no local variations. Fraction display rounds to the chosen denominator.
Limitations: Fraction formatting is for readability; underlying math uses full precision before rounding.
Results interpretation
- Decimal rounding: adjust to match plan tolerances or print specs.
- Fraction-inch display: pick 1/16″ for trim, 1/8″ for framing, 1/4″ for rough estimates.
- Consistency: stick to one rounding rule across a project to avoid mismatch.
Use cases & examples
Example 1: 1.25 in → 3.175 cm; nearest 1/16″ → 1 1/4″.
Example 2: 18 cm → 7.0866 in; nearest 1/8″ → 7 1/8″.
Example 3: 0.625 in → 1.5875 cm; nearest 1/16″ → 5/8″.
Inches ↔ centimeters — FAQ
What is the exact conversion between inches and centimeters?
1 inch equals 2.54 centimeters exactly. The inverse is 1 cm = 0.3937007874 in.
How does the fraction-inch helper work?
We round the decimal inch to the nearest selected denominator (1/2, 1/4, 1/8, or 1/16) and format it as a mixed number.
Can I type in centimeters instead of inches?
Yes. Edit either field and we detect the direction automatically.
Should I use decimals or fractions for woodworking?
Fractions are familiar on a tape measure. Pick 1/16″ for trim, 1/8″ for framing, or use decimals if your tools prefer them.
Do you round before conversion?
No. We convert with full precision and apply your rounding afterwards for display.
Why do my tape readings sometimes differ slightly?
Small differences come from rounding rules and reading habits. Use one rounding rule consistently throughout a project.
Inches to centimeters: precise conversion and practical measuring
We convert between inches and centimeters with exact constants so measurements are predictable across plans, tools, and suppliers. The fraction-inch helper mirrors how many pros read a tape: whole inches plus a simple fraction.
Where each unit shines
Centimeters work well for metric drawings and science contexts; inches remain common in U.S. construction and woodworking. Our converter keeps both sides aligned so you can collaborate across standards without confusion.
Choosing rounding for real projects
Pick coarse rounding for rough framing, tighter rounding for cabinetry or 3D prints. You can switch rounding any time—inputs persist.