Convert millimeters, centimeters, meters, or kilometers to inches (decimal and fractional). Includes feet-inches, yards, and common-object reference.
Metric-to-inches conversion is one of the most common unit translations in everyday life — from reading international product dimensions to cutting lumber, fitting pipes, or comparing screen sizes. The key factor is 25.4: one inch equals exactly 25.4 millimeters under the international definition used in modern engineering standards and technical documentation across industries.
This calculator converts any metric length (mm, cm, m, or km) to decimal inches, fractional inches (to the nearest 1/64″), feet-and-inches, feet, and yards — all at once. A large heading shows the primary result, and six output cards display every practical imperial equivalent. Preset buttons load typical sizes, and a reference table lists common objects alongside their metric and fractional-inch measurements.
Whether you're interpreting a European furniture spec, converting a metric bolt size, measuring fabric, or sizing a TV screen, this tool eliminates mental math and delivers precise decimal and fractional inch results in one step.
Anyone working across metric and imperial systems faces this conversion daily. Hardware specs from Europe list millimeters; US tools and lumber use inches. Screen sizes are in inches worldwide, but physical dimensions are in mm. This calculator handles all metric prefixes and outputs both decimal and fractional inches — something most generic converters skip.
The fractional-inch output is especially valuable for woodworkers, machinists, and plumbers who need to match drill bits, wrenches, and pipe fittings that are labeled in 1/16 or 1/32 increments.
Metric to Inches: inches = value_in_mm ÷ 25.4. Normalize inputs first: mm from cm (×10), m (×1,000), km (×1,000,000). Fractional inches are rounded to the nearest 1/64 and simplified. 1 ft = 12 in; 1 yd = 36 in.
Result: 12 inches (1 foot)
30.48 cm = 304.8 mm ÷ 25.4 = 12 inches exactly. That is 1 foot or ⅓ yard.
The international inch was standardized in 1959 at exactly 25.4 mm. Before that, US and British inches differed slightly. The 1959 agreement unified the inch across all participating countries, making metric-to-inch conversion mathematically exact — no rounding involved. This is why 1 foot = 304.8 mm exactly, and 1 yard = 914.4 mm exactly.
The US still uses fractional inches in many trades: 1/2″, 3/8″, 5/16″, 7/32″, and so on. Decimal inches (0.125″) are more common in engineering. Both notations coexist, which can confuse anyone not used to switching. This calculator shows both so you can match whichever system a spec or tool uses.
**Home improvement:** Metric screws and anchors from IKEA need to be matched with US drill bits labeled in fractional inches. **Cooking:** European recipe equipment like cake pans list centimeter diameters; US pans list inches. **Sewing & fabric:** European patterns use centimeters for seam allowances and garment dimensions; US sewers think in inches. **Electronics:** Component datasheets show millimeter footprints; PCB tools may use mil (thousandths of an inch). This tool bridges all those gaps.
One centimeter equals approximately 0.3937 inches. To convert cm to inches, divide by 2.54.
One inch equals exactly 25.4 millimeters. This is an exact definition, not an approximation.
Divide mm by 25.4 to get decimal inches, then round to the nearest fraction (1/16, 1/32, or 1/64). This calculator does it automatically.
In 1959, the US, UK, and other countries agreed on 1 international inch = 25.4 mm by treaty, making the conversion exact by definition.
Multiply meters by 39.3701 to get total inches, then divide by 12 for feet and take the remainder as inches. This calculator shows both formats.
In woodworking, plumbing, and US manufacturing, measurements are often given in fractions like 3/8″ or 5/16″ instead of decimals. Fractions are based on halving: 1/2, 1/4, 1/8, 1/16, 1/32, 1/64.