--- title: "Length Conversion Guide: Formulas, Charts & DIY Examples | ShoutingNow" description: "Convert length for construction and DIY: cm, inches, feet, and meters with plain formulas, pre-calculated tables, worked examples, and free converter tools." url: "https://shoutingnow.com/guides/unit-conversion-guide/length-conversion/" image: "https://shoutingnow.com/wp-content/uploads/2026/07/Length-Conversion-Guide-cm-mm-Inches-Feet-and-Meters-1024x683.webp" --- # Length Conversion Guide: Formulas, Charts & DIY Examples **Length conversion** is what you do when a lumber yard lists boards in feet and inches, a European furniture site shows centimeters, or a site plan mixes meters with fractional inches. On a job site or in a weekend DIY project, the wrong scale turns a clean cut into a gap, or a piece that will not fit the opening. This guide covers the formulas, tables, and worked examples you need for everyday length conversion, then links every ShoutingNow length tool. On this page 13 1. 1 What length conversion is (and why it matters on site) 2. 2 Plain-language length formulas 3. 3 Length conversion tables Centimeters to inches 4. Feet to meters [ 4 Worked examples ](#worked-examples) 1. Example 1, shelf depth from a metric listing 2. Example 2, stud bay to metric hardware 3. Example 3, driveway stake spacing [ 5 Common length conversion mistakes ](#common-length-conversion-mistakes) [ 6 Length converter tools ](#length-converter-tools) [ 7 Related reading ](#related-reading) [ 8 Frequently asked questions ](#sn-section-faqs) Show 3 more sections **Convert length now:** [Open the free Length Converter](https://shoutingnow.com/tools/length-converter/), pick any from/to pair, enter a value, and get an instant result. No sign-up required. ## What length conversion is (and why it matters on site) Length measures one dimension: how far from A to B. Converting length means rewriting that same distance in another unit, inches to centimeters, feet to meters, millimeters to inches, without changing the physical size. Builders, remodelers, and makers hit this constantly: tape measures in inches, product specs in mm, architectural drawings in meters, and online orders that switch systems mid-cart. Unlike area or volume, length factors are linear. Double the number of inches and you double the centimeters. That simplicity is helpful, until mixed feet-and-inches notation or early rounding throws a cut list off by a few millimeters. ## Plain-language length formulas Memorize a few anchors; use a converter when you need many decimals: - Inches ↔ centimeters: multiply inches by 2.54 for cm (exact). Divide cm by 2.54 for inches. - Feet ↔ inches: multiply feet by 12. Divide inches by 12 for feet (keep the remainder as inches when you need ft/in). - Meters ↔ feet: multiply meters by 3.28084 for feet. Divide feet by 3.28084 for meters. - Millimeters ↔ inches: divide mm by 25.4 for inches. Multiply inches by 25.4 for mm. - Miles ↔ kilometers: multiply miles by 1.60934 for km. For feet-and-inches as a single height or cut (for example 5 ft 7 in), convert the whole quantity to inches first, then to metric, or use a dedicated feet-inches tool so you do not drop the inch remainder. ## Length conversion tables ### Centimeters to inches cm inches (approx.) 2.5 0.98 10 3.94 30 11.81 91.44 36.00 (3 ft) 152.4 60.00 (5 ft) ### Feet to meters feet meters (approx.) 1 0.305 8 2.438 12 3.658 16 4.877 25 7.620 Need a one-off pair? Try the [centimeters to inches converter](https://shoutingnow.com/tools/centimeters-to-inches-converter/) or the [feet to meters converter](https://shoutingnow.com/tools/feet-to-meters-converter/). ## Worked examples ### Example 1, shelf depth from a metric listing An online shelf is listed as **38.5 cm** deep. Your wall niche was framed to **15 in**. Convert: 38.5 ÷ 2.54 ≈ **15.16 in**. The shelf is about 0.16 in deeper than the niche, too tight without trimming or a different SKU. ### Example 2, stud bay to metric hardware A rough opening is **6 ft 3 in** wide. Total inches: (6 × 12) + 3 = **75 in**. In meters: 75 × 0.0254 = **1.905 m**. Order metric trim or glass to that clear width, not to “about 1.9 m” rounded early. ### Example 3, driveway stake spacing Plans call for posts every **2.75 m**. In feet: 2.75 × 3.28084 ≈ **9.02 ft** (about 9 ft ¼ in). Mark the tape at 9 ft 0 in and add a quarter inch rather than guessing “nine feet.” ## Common length conversion mistakes - Treating feet-inches as a decimal. “5.7 ft” is not the same as 5 ft 7 in (5.7 ft = 5 ft 8.4 in). - Squaring a length factor for area. Length uses 2.54 for in↔cm; area uses 2.54². Do not reuse length factors on floor plans. - Rounding mid-cut list. Convert once at full precision, then round the final mark on the board. - Mixing mm and cm on the same drawing. Confirm the drawing unit before you scale a dimension. ## Length converter tools Start with the multi-unit [Length Converter](https://shoutingnow.com/tools/length-converter/), or jump to a dedicated pair: - Length Converter - Centimeters to Feet Converter - Centimeters to Feet Inches Converter - Centimeters to Inches Converter - Feet to Inches Converter - Feet to Meters Converter - Feet Inches to Meters Converter - Inches to Centimeters Converter - Inches to Feet Converter - Meters to Feet & Inches Converter - MM to Inches Converter - Micrometers to Meters Converter - Nanometers to Meters Converter - Miles to Kilometers Converter - Picas to Inches Converter - Points to Inches Converter ## Related reading - Construction measurement tips, trade and DIY habits that keep cuts and layouts accurate - Unit conversion chart & calculator guide, map of every category guide on ShoutingNow ## Frequently Asked Questions ### How do I convert inches to centimeters for a cut list? Multiply inches by 2.54, which is an exact figure. A 14.5 in cut works out to 14.5 × 2.54 = 36.83 cm. If you have a lot of pairs to run, the [Length Converter](https://shoutingnow.com/tools/length-converter/) saves you the repetitive math. ### Is 5.7 feet the same as 5 feet 7 inches? They are not, and mixing them up is a classic job-site error. 5.7 ft means 5 ft plus 0.7 × 12 = 8.4 in, while five feet seven inches is 5 + 7/12 ≈ 5.583 ft. Separate feet from inches before you convert to metric. ### How many feet are in a meter on a job site? About 3.28084 feet per meter, so a 2.4 m sheet comes out to roughly 7.87 ft. Convert once at full precision for framing and openings, then mark your tape from that number. ### Can I reuse a length factor when converting floor area? No, area needs its length factor squared. Inches to cm uses 2.54, but square inches to cm² uses about 6.4516 instead. The [area conversion guide](https://shoutingnow.com/guides/unit-conversion-guide/area-conversion/) covers lot and floor sizes properly. ### Where can I get construction-focused measurement tips? [Construction measurement tips](https://shoutingnow.com/blog/construction-measurement-tips/) covers the trade and DIY habits worth knowing, then you can come back here for the length formulas and converter links. ### Are ShoutingNow length converters free? They are, the Length Converter and every dedicated length pair tool run in your browser with no account needed. ```json [{"@context":"https://schema.org","@type":"Organization","name":"ShoutingNow","url":"https://shoutingnow.com/","logo":{"@type":"ImageObject","url":"https://shoutingnow.com/wp-content/themes/shoutingnow-theme/assets/images/logo.png"},"sameAs":["https://x.com/makani20","https://www.linkedin.com/in/makani20/","https://post-see.com"],"contactPoint":{"@type":"ContactPoint","contactType":"customer support","email":"support@shoutingnow.com","url":"https://shoutingnow.com/contact/"},"slogan":"Learn. Build. 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