Why Unit Conversion Matters in Daily Life单位换算在生活中的重要性
Whether you are following a recipe, checking product specs, or comparing prices across countries, you often need to convert between metres and feet, kilograms and pounds, or other units. A simple, local unit converter gives you instant results without sending your input to any server—ideal for quick checks at home, in the office, or while travelling.无论是按菜谱下厨、查看产品规格，还是跨国比价，都常需要在米与英尺、公斤与磅等单位之间换算。一款简单、本地的单位换算器能即时给出结果且不把输入上传到任何服务器，适合在家、办公室或出行时快速查询。
Metric vs. Imperial: A Quick Overview公制与英制：简要说明
Most of the world uses the metric system (metres, kilograms, litres). The United States and a few other countries still use imperial or US customary units (feet, pounds, gallons). Recipes, fitness goals, and product labels often mix both, so being able to convert quickly avoids confusion and errors. Our tool supports length (e.g. m, km, cm, in, ft) and weight (e.g. kg, g, lb) so you can switch between systems in one place.世界上多数地区使用公制（米、公斤、升）；美国等少数国家仍常用英制或美制单位（英尺、磅、加仑）。菜谱、健身目标和商品标签常混用两种制度，能快速换算可以避免搞错。本工具支持长度（如米、千米、厘米、英寸、英尺）和重量（如公斤、克、磅），方便在同一页面内切换制度。
When to Convert Length and Weight何时需要换算长度与重量
Length conversion is useful for DIY projects, room dimensions, and understanding height or distance in a familiar unit. Weight conversion helps with cooking, shipping, and comparing product weights. Use the swap button to flip source and target units quickly. All calculations run in your browser—no data is stored or sent elsewhere, so you can use the converter offline once the page is loaded.长度换算常用于 DIY、房间尺寸，以及用自己熟悉的单位理解身高或距离。重量换算则有助于下厨、寄件和对比商品重量。使用交换按钮可快速对调“从”与“到”的单位。所有计算均在浏览器内完成，数据不会保存或上传，页面加载后离线也可使用。
Accuracy and Rounding精度与四舍五入
Conversion factors are based on standard definitions (e.g. 1 inch = 0.0254 m, 1 lb ≈ 0.45359 kg). Results are shown with enough decimal places for everyday use; for scientific or legal purposes, always verify with official sources. This tool is meant for quick, practical conversions—not as the sole basis for critical decisions.换算系数基于标准定义（如 1 英寸 = 0.0254 米，1 磅 ≈ 0.45359 公斤）。结果为日常使用保留了足够小数位；若用于科研或法律场景，请以官方资料为准。本工具面向快速、实用的换算，不宜作为重大决策的唯一依据。
Why Use a Local Converter为何选择本地换算器
Online unit converters that send your input to a server can log or analyse your data. This converter runs entirely in your browser: you type a value, choose units, and see the result instantly. No account, no tracking, and no data leaves your device. That makes it suitable for quick checks at home, in the office, or while travelling, without privacy concerns. Once the page is loaded, you can even use it offline.将输入上传到服务器的在线换算器可能会记录或分析你的数据。本换算器完全在浏览器内运行：输入数值、选择单位即可看到结果。无需账号、无追踪、数据不会离开你的设备，适合在家、办公室或出行时快速查询，且不必担心隐私。页面加载后，离线也可使用。
Length Conversion: From DIY to Travel长度换算：从 DIY 到出行
Length is one of the most common conversion needs. If you are following a plan in metres but your tape measure is in feet and inches, a quick conversion avoids mistakes. Travellers often need to convert between kilometres and miles for distance, or centimetres and inches for luggage or height. Builders and gardeners switch between metres, feet, and sometimes centimetres depending on the project. Our length category supports metres, kilometres, centimetres, inches, and feet, so you can move between metric and imperial without looking up conversion factors yourself.长度是最常需要换算的类别之一。若图纸用米、卷尺用英尺和英寸，快速换算能避免出错。出行时常用公里与英里换算距离，或用厘米与英寸换算行李或身高。建筑和园艺则常在米、英尺、厘米之间切换。本工具的长度类别支持米、千米、厘米、英寸、英尺，可在公制与英制间自由切换，无需自己查换算系数。
Weight Conversion: Cooking, Shipping, and Fitness重量换算：下厨、寄件与健身
Weight conversion is useful in the kitchen when a recipe uses grams but your scale shows ounces or pounds, or when you are scaling a recipe up or down. When shipping packages, courier services often use kilograms while you might think in pounds. In fitness, people track body weight or lifting loads in either kilograms or pounds depending on where they live or train. Our weight category includes kilograms, grams, and pounds, with conversion factors based on standard definitions so that your results are consistent and reliable for everyday use.下厨时菜谱用克、秤用盎司或磅，或要按比例缩放配方时，重量换算很实用。寄件时快递多用公斤，而你可能习惯用磅。健身时体重或负重常用公斤或磅，因地区或习惯而异。本工具重量类别包含公斤、克和磅，换算系数按标准定义，结果一致可靠，便于日常使用。
How Conversion Factors Are Chosen换算系数如何确定
Conversion factors are fixed by international agreement or long-standing convention. For example, one inch is defined as exactly 0.0254 metres; one pound is approximately 0.45359237 kilograms. Using these standard values ensures that everyone gets the same result when converting between units. Small rounding differences can appear when you go back and forth many times, but for single conversions the tool gives enough decimal places for practical use. For scientific, legal, or commercial applications where exact figures matter, always double-check with official references.换算系数由国际协议或惯例确定。例如 1 英寸精确定义为 0.0254 米，1 磅约等于 0.45359237 公斤。采用这些标准值可保证所有人换算结果一致。多次往返换算时可能出现细微舍入差异，但单次换算时工具会保留足够小数位供日常使用。若用于科研、法律或商业等对精确数字有要求的场景，请以官方资料为准。