Free online tools for unit conversion, colors, fonts, images, text & news.
Tools for everyone. Convert units, generate color palettes, browse fonts, compress images, edit text, and explore tech history, all free, no sign-up required.
概要
OmniConverter は、正確性、スピード、シンプルさを追求した無料のオンライン単位変換ツールです。リアルタイム為替レート付きの通貨換算、マイルとキロメートルの長さ換算、キログラムとポンドの重量換算、摂氏と華氏の温度換算など、すべてがここに揃っています。
OmniConverter は靴・衣類サイズ換算といった日常的な用途から、デジタルストレージ、電流、周波数、タイポグラフィ単位といった技術的な用途まで幅広くカバーします。すべての変換ツールは無料、アカウント登録不要、あらゆるデバイスで瞬時に動作し、丸めた近似値ではなく正確な換算係数を使用します。世界中の学生、専門家、旅行者、開発者に信頼されています。
選ばれる理由
学生、エンジニア、旅行者、開発者まで誰でも使える、プロ仕様の精度。
入力と同時に、正確な換算係数で計算を実行。丸めた推定値ではありません。
20 種類すべての単位に科学的に正確な公式を採用。常に正確で信頼できます。
為替レートは継続的に更新。150 以上の通貨と主要な暗号通貨に対応。
デスクトップ、タブレット、モバイル向けに完全最適化。いつでもどこでも変換できます。
アカウントもサブスクも、結果を妨げる広告もなし。開いてすぐ変換。
メートル法、ヤード・ポンド法、米国慣用単位、各地域のサイズ規格に対応。
クイックリファレンス
よくある換算の疑問に即答, 行をクリックしてライブ変換ツールを使用できます。
| 換算 | 答え | カテゴリ | 試す |
|---|---|---|---|
| 1 mile to km | 1 mile = 1.609 km | 長さ | 変換 |
| kg to lbs | 1 kg = 2.205 lbs | 重量 | 変換 |
| Celsius to Fahrenheit | °F = (°C × 9/5) + 32 | 熱 | 変換 |
| USD to EUR | Live rate | 通貨 | 変換 |
| 1 gallon to liters | 1 US gal = 3.785 L | 体積 | 変換 |
| inches to cm | 1 inch = 2.54 cm | 長さ | 変換 |
| 1 acre to sq ft | 1 acre = 43,560 sq ft | 面積 | 変換 |
| mph to km/h | 1 mph = 1.609 km/h | 速度 | 変換 |
| 1 GB to MB | 1 GB = 1,024 MB | ストレージ | 変換 |
| 1 stone to kg | 1 stone = 6.350 kg | 重量 | 変換 |
ご利用者
教室から建設現場まで、測定単位を扱うすべての人のために。
物理の宿題から地理の授業まで。カリキュラムのあらゆる単位, メートル法、ヤード・ポンド法、科学単位, をカバー。
異なる通貨、気温、衣類サイズを簡単に変換。すべてを数秒で。
力、圧力、エネルギー、電力、電流など、エンジニアリングに必要なあらゆる単位を正確に換算。
レシピをカップからグラムへ、華氏から摂氏へ調整？海外レシピもシンプルに。
海外ブランドの靴・衣類サイズや通貨の価格を瞬時に解読。
px、pt、em、バイト、周波数を扱う？技術業務のために技術的精度で構築。
Free • Accurate • Private
You know the feeling: a recipe says cups, your scale says grams. A listing says square feet, you think in square meters. A flight lands and you need USD to EUR before you pay. OmniConverter was built for those small, nagging moments — a free online converter where you type once and see every relevant unit at once, metric and imperial, without juggling tabs.
It covers the everyday and the specialist — length, weight, temperature, area, volume, speed, time, currency, digital storage, plus shoe and clothing sizes, pressure, fuel economy and more — over 20 categories grounded in exact BIPM, NIST and ISO 80000 factors. Whether it’s miles to kilometers, kilos to pounds, Celsius to Fahrenheit, or liters to gallons, you get a clear, trustworthy answer you can act on.
And because life isn’t just numbers, the same suite gives you OmniColors for palettes and gradients, OmniFonts to preview 200+ Google Fonts, OmniImages to compress or convert photos in the browser, OmniDocuments for quick PDF fixes, and OmniText for clean word counts — all free, private (your values never leave your device), and built to feel light on mobile. If you found us by searching online converter, free unit converter, measurement conversion, stay a moment and try one conversion. Most people bookmark it after the first.
It’s fast without feeling rushed. You type, every unit updates live. The math is honest — no rounding until the last display, no “close enough.” No account, no clutter, and it works beautifully on your phone. That’s why students, cooks, travelers, engineers, and shoppers tend to keep OmniConverter open in the background, quietly handling the conversions while they get on with what they actually wanted to do.
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Explore OmniImagesMerge, split, reorder, compress PDFs, and convert between PDF, Word, and Excel, free document tools for professionals.
Explore OmniDocumentsLatest news, sports, weather, travel, business, politics, and technology, curated news coverage across 7 sections.
Explore OmniNewsGenerate branded QR codes with your logo. Download as transparent PNG or scalable SVG, free, no sign-up required.
Create QR CodeOmniConverter is a free online converter suite for 20+ categories — length, weight, temperature, currency, area, volume, speed, digital storage and more — with live results, exact BIPM/NIST factors, and no sign-up.
Pick a category (e.g., length), choose from and to units, type a value — every unit updates instantly. Example: 5 meters = 16.404 feet. Works for metric to imperial and back.
Yes — factors are from BIPM SI brochure and NIST SP 811, stored unrounded and computed in double precision via a base unit. Conversions run client-side; we do not store your values.
Yes — 150+ currencies + crypto, base USD, daily updates from Frankfurter/ECB. Search “USD to EUR” or open the currency converter for live rates.
Yes — shoe size and clothing size converters use regional tables (US, UK, EU, AU) with cm/inches for precise online shopping conversions.
Yes — English, Spanish, French, German, Chinese, Japanese, Hindi and Arabic, with localized converters and 8-way hreflang for SEO.
OmniConverter is free and built with care. If it helps you, consider supporting its development.
Tips, guides, and insights about unit conversions
One meter equals 100 centimeters exactly by SI definition. Learn the m-to-cm formula, instant conversion table and how to avoid confusing m→cm with cm→m.
Read More about M to CM: How Many Centimeters in a Meter? Instant ConversionConvert MPG to km/L and L/100 km without errors. US vs UK gallon formulas (×0.425, 235.215÷MPG) plus tables, examples and FAQs for accurate fuel-economy math.
Read More about MPG to KM/L: Convert Miles Per Gallon to Kilometers Per Liter
Why is a UK gallon 4.546 litres vs US 3.785 L — 20% larger? Discover imperial history, Brexit labelling rules, exact formulas and conversion tables for drivers.
Read More about Gallons to Litres UK: Why Your UK Gallon Is BiggerSince 2019 the kilogram is defined by Planck's constant, not a Paris metal block. Learn what mass is and how kg, pounds and stones translate precisely now.
Read More about The Kilogram Redefined: How Planck's Constant Replaced a Metal Cylinder and Why Mass Matters
Why do ships use knots and jets use Mach? Explore how knots, mph, km/h and Mach numbers measure speed differently for road, sea and air navigation each day.
Read More about Knots, Mach and Kilometers per Hour: The Speed Units Pilots, Sailors and Drivers Rely On
Learn how many liters in a US gallon (3.785 L) vs UK imperial gallon (4.546 L). Compare formulas, see a 1–10 L conversion table and avoid common mistakes.
Read More about Liters to Gallons: How Many Liters in a Gallon? US vs UK Explained
US listings show square feet and EU uses square meters. Learn how acres, hectares and square meters translate for housing, farmland and planning daily.
Read More about Square Meters, Acres and Hectares: How the World Measures Land, Housing and Farms
A US gallon is 3.785 liters, a UK gallon is 4.546. Learn how liters, gallons, cubic meters and fluid ounces convert across cooking, fuel and industrial design.
Read More about Liters, Gallons and Cubic Meters: A Global Guide to Volume in Kitchens and Factories
Pushing a cart and launching a rocket both use force, but one counts newtons and the other pound-force. Learn how these units translate in daily real life.
Read More about Newtons vs Pounds-Force: Understanding Force Units in Engineering and Everyday Life
A kettle is 2000 watts, a car is 300 horsepower. Learn how watts, kilowatts and horsepower measure the same thing—rate of energy use—across homes and vehicles.
Read More about Watts vs Horsepower: What Power Really Means From Light Bulbs to Electric CarsWhy does a 512 GB phone show only 476 GB usable? Understand bits, bytes, KB to TB, the 1024 vs 1000 split, and how to size storage accurately for backups.
Read More about Bits to Terabytes: Why Digital Storage Uses 1024 and How Much Space You Really Need
Food labels show 250 kcal while bills show 300 kWh. Learn how joules, calories and kilowatt-hours track the same energy across cooking and power grids.
Read More about Calories to Kilowatt-Hours: How Energy Units Connect Food, Fuel and Electricity Bills
